f2fs: avoid BUG_ON from check_nid_range and update return path in do_read_inode

In function check_nid_range, there is no need to trigger BUG_ON and make kernel stop.
Instead it could just check and indicate the inode number to be EINVAL.
Update the return path in do_read_inode to use the return from check_nid_range.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
[Jaegeuk: replace BUG_ON with WARN_ON]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index be7ae70..06ff6a5 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -515,9 +515,12 @@
 /*
  * Check whether the given nid is within node id range.
  */
-static inline void check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
+static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
 {
-	BUG_ON((nid >= NM_I(sbi)->max_nid));
+	WARN_ON((nid >= NM_I(sbi)->max_nid));
+	if (nid >= NM_I(sbi)->max_nid)
+		return -EINVAL;
+	return 0;
 }
 
 #define F2FS_DEFAULT_ALLOCATED_BLOCKS	1