media: staging: media: imx7-mipi-csis: fix debugfs compilation

When CONFIG_DEBUGFS is enabled, we get a warning about an
incorrect section annotation that can lead to undefined
behavior:

WARNING: vmlinux.o(.text+0xd3c7c4): Section mismatch in reference from the function mipi_csis_probe() to the function .init.text:mipi_csis_debugfs_init()
The function mipi_csis_probe() references
the function __init mipi_csis_debugfs_init().
This is often because mipi_csis_probe lacks a __init
annotation or the annotation of mipi_csis_debugfs_init is wrong.

The same function for an unknown reason has a different
version for !CONFIG_DEBUGFS, which does not have this problem,
but behaves the same way otherwise (it does nothing when debugfs
is disabled).
Consolidate the two versions, using the correct section from
one version, and the implementation from the other.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/imx/imx7-mipi-csis.c

@@ -9,6 +9,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/debugfs.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
@@ -889,8 +890,6 @@ static int mipi_csis_subdev_init(struct v4l2_subdev *mipi_sd,
 	return ret;
 }
 
-#ifdef CONFIG_DEBUG_FS
-#include <linux/debugfs.h>
 
 static int mipi_csis_dump_regs_show(struct seq_file *m, void *private)
 {
@@ -900,7 +899,7 @@ static int mipi_csis_dump_regs_show(struct seq_file *m, void *private)
 }
 DEFINE_SHOW_ATTRIBUTE(mipi_csis_dump_regs);
 
-static int __init_or_module mipi_csis_debugfs_init(struct csi_state *state)
+static int mipi_csis_debugfs_init(struct csi_state *state)
 {
 	struct dentry *d;
 
@@ -934,17 +933,6 @@ static void mipi_csis_debugfs_exit(struct csi_state *state)
 	debugfs_remove_recursive(state->debugfs_root);
 }
 
-#else
-static int mipi_csis_debugfs_init(struct csi_state *state __maybe_unused)
-{
-	return 0;
-}
-
-static void mipi_csis_debugfs_exit(struct csi_state *state __maybe_unused)
-{
-}
-#endif
-
 static int mipi_csis_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;