f2fs: avoid build warning

This patch removes the following build warning:
fs/f2fs/node.c: warning: 'nofs' may be used uninitialized in this function
[-Wuninitialized]:  => 738:8

Note that this is a false alarm.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 0da252c..e275218 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -660,7 +660,7 @@
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	int err = 0, cont = 1;
 	int level, offset[4], noffset[4];
-	unsigned int nofs;
+	unsigned int nofs = 0;
 	struct f2fs_node *rn;
 	struct dnode_of_data dn;
 	struct page *page;