f2fs: Add inline to f2fs_build_fault_attr() stub

commit 0d89682 upstream.

When building without CONFIG_F2FS_FAULT_INJECTION, there is a warning
from each file that includes f2fs.h because the stub for
f2fs_build_fault_attr() is missing inline:

  In file included from fs/f2fs/segment.c:21:
  fs/f2fs/f2fs.h:4605:12: warning: 'f2fs_build_fault_attr' defined but not used [-Wunused-function]
   4605 | static int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
        |            ^~~~~~~~~~~~~~~~~~~~~

Add the missing inline to resolve all of the warnings for this
configuration.

Fixes: 4ed886b ("f2fs: check validation of fault attrs in f2fs_build_fault_attr()")
Signed-off-by: Nathan Chancellor <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
(cherry picked from commit 72d0e1dec7914b36beb4f3c7fe3a4c01cbb018ee linux-6.9.y)
CVE-2024-42160
Signed-off-by: Massimiliano Pellizzer <[email protected]>
Acked-by: Aaron Jauregui <[email protected]>
Acked-by: Kuan-Ying Lee <[email protected]>
Signed-off-by: Manuel Diewald <[email protected]>

fs/f2fs/f2fs.h

@@ -4606,8 +4606,8 @@ static inline bool f2fs_need_verity(const struct inode *inode, pgoff_t idx)
 extern int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
 							unsigned long type);
 #else
-static int f2fs_build_fault_attr(struct f2fs_sb_info *sbi, unsigned long rate,
-							unsigned long type)
+static inline int f2fs_build_fault_attr(struct f2fs_sb_info *sbi,
+					unsigned long rate, unsigned long type)
 {
 	return 0;
 }