staging: prefix header search paths with $(srctree)/

Currently, the Kbuild core manipulates header search paths in a crazy
way [1].

To fix this mess, I want all Makefiles to add explicit $(srctree)/ to
the search paths in the srctree. Some Makefiles are already written in
that way, but not all. The goal of this work is to make the notation
consistent, and finally get rid of the gross hacks.

Having whitespaces after -I does not matter since commit 48f6e3cf
("kbuild: do not drop -I without parameter").

[1]: https://patchwork.kernel.org/patch/9632347/Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/erofs/Makefile

@@ -6,7 +6,7 @@ ccflags-y += -Wall -DEROFS_VERSION=\"$(EROFS_VERSION)\"
 
 obj-$(CONFIG_EROFS_FS) += erofs.o
 # staging requirement: to be self-contained in its own directory
-ccflags-y += -I$(src)/include
+ccflags-y += -I $(srctree)/$(src)/include
 erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
 erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
 erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_vle_lz4.o

drivers/staging/media/davinci_vpfe/Makefile

@@ -6,5 +6,5 @@ davinci-vfpe-objs := \
 
 # Allow building it with COMPILE_TEST on other archs
 ifndef CONFIG_ARCH_DAVINCI
-ccflags-y += -Iarch/arm/mach-davinci/include/
+ccflags-y += -I $(srctree)/arch/arm/mach-davinci/include/
 endif

drivers/staging/most/Makefile

 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_MOST) += most_core.o
 most_core-y := core.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/
 
 obj-$(CONFIG_MOST_CDEV)	+= cdev/
 obj-$(CONFIG_MOST_NET)	+= net/

drivers/staging/most/cdev/Makefile

 obj-$(CONFIG_MOST_CDEV) += most_cdev.o
 
 most_cdev-objs := cdev.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/most/dim2/Makefile

 obj-$(CONFIG_MOST_DIM2) += most_dim2.o
 
 most_dim2-objs := dim2.o hal.o sysfs.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/most/i2c/Makefile

 obj-$(CONFIG_MOST_I2C) += most_i2c.o
 
 most_i2c-objs := i2c.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/most/net/Makefile

 obj-$(CONFIG_MOST_NET) += most_net.o
 
 most_net-objs := net.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/most/sound/Makefile

 obj-$(CONFIG_MOST_SOUND) += most_sound.o
 
 most_sound-objs := sound.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/most/usb/Makefile

 obj-$(CONFIG_MOST_USB) += most_usb.o
 
 most_usb-objs := usb.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/most/video/Makefile

 obj-$(CONFIG_MOST_VIDEO) += most_video.o
 
 most_video-objs := video.o
-ccflags-y += -Idrivers/staging/
+ccflags-y += -I $(srctree)/drivers/staging/

drivers/staging/rtl8192u/Makefile

@@ -7,7 +7,7 @@ ccflags-y += -O2
 ccflags-y += -DCONFIG_FORCE_HARD_FLOAT=y
 ccflags-y += -DJACKSON_NEW_8187 -DJACKSON_NEW_RX
 ccflags-y += -DTHOMAS_BEACON -DTHOMAS_TASKLET -DTHOMAS_SKB -DTHOMAS_TURBO
-ccflags-y += -Idrivers/staging/rtl8192u/ieee80211
+ccflags-y += -I $(srctree)/$(src)/ieee80211
 
 r8192u_usb-y := r8192U_core.o r8180_93cx6.o r8192U_wx.o		\
 		  r8190_rtl8256.o r819xU_phy.o r819xU_firmware.o	\

drivers/staging/unisys/visorhba/Makefile

@@ -6,5 +6,4 @@ obj-$(CONFIG_UNISYS_VISORHBA)	+= visorhba.o
 
 visorhba-y := visorhba_main.o
 
-ccflags-y += -Idrivers/staging/unisys/include
-
+ccflags-y += -I $(srctree)/$(src)/../include

drivers/staging/unisys/visornic/Makefile

@@ -6,5 +6,4 @@ obj-$(CONFIG_UNISYS_VISORNIC)	+= visornic.o
 
 visornic-y := visornic_main.o
 
-ccflags-y += -Idrivers/staging/unisys/include
-
+ccflags-y += -I $(srctree)/$(src)/../include

drivers/staging/vc04_services/bcm2835-audio/Makefile

 obj-$(CONFIG_SND_BCM2835)	+= snd-bcm2835.o
 snd-bcm2835-objs		:= bcm2835.o bcm2835-ctl.o bcm2835-pcm.o bcm2835-vchiq.o
 
-ccflags-y += -Idrivers/staging/vc04_services -D__VCCOREVER__=0x04000000
-
+ccflags-y += -I $(srctree)/$(src)/.. -D__VCCOREVER__=0x04000000

drivers/staging/vc04_services/bcm2835-camera/Makefile

@@ -7,5 +7,5 @@ bcm2835-v4l2-$(CONFIG_VIDEO_BCM2835) := \
 obj-$(CONFIG_VIDEO_BCM2835) += bcm2835-v4l2.o
 
 ccflags-y += \
-	-Idrivers/staging/vc04_services \
+	-I $(srctree)/$(src)/.. \
 	-D__VCCOREVER__=0x04000000