f2fs: Fix wrong stub helper update_sit_info

update_sit_info should be f2fs_update_sit_info,
otherwise build fails while no CONFIG_F2FS_STAT_FS.

Fixes: fc7100ea ("f2fs: Add f2fs stats to sysfs")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -3728,7 +3728,7 @@ static inline int f2fs_build_stats(struct f2fs_sb_info *sbi) { return 0; }
 static inline void f2fs_destroy_stats(struct f2fs_sb_info *sbi) { }
 static inline void __init f2fs_create_root_stats(void) { }
 static inline void f2fs_destroy_root_stats(void) { }
-static inline void update_sit_info(struct f2fs_sb_info *sbi) {}
+static inline void f2fs_update_sit_info(struct f2fs_sb_info *sbi) {}
 #endif
 
 extern const struct file_operations f2fs_dir_operations;