Kbuild: avoid duplicate include path

arch/$(hdr-arch)/include/generated/uapi is included twice in the
header search path, which is unnecessary, so this changes the
top-level Makefile to drop the second instance by filtering out
everything from USERINCLUDE that was already part of LINUXINCLUDE.

This should have very little effect other than making the 'make V=1'
output slightly smaller and making the build time faster by a miniscule
amount, but it seems to be cleaner.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Marek <mmarek@suse.com>

Makefile

@@ -387,8 +387,9 @@ LINUXINCLUDE    := \
 		-Iarch/$(hdr-arch)/include/generated/uapi \
 		-Iarch/$(hdr-arch)/include/generated \
 		$(if $(KBUILD_SRC), -I$(srctree)/include) \
-		-Iinclude \
-		$(USERINCLUDE)
+		-Iinclude
+
+LINUXINCLUDE	+= $(filter-out $(LINUXINCLUDE),$(USERINCLUDE))
 
 KBUILD_CPPFLAGS := -D__KERNEL__