nilfs2: add missing initialization of s_mode

An fmode_t argument is passed to kill_block_super() through s_mode
member of the super_block structure.  This is used to release the
block device with the same mode, however, nilfs does not set s_mode
anywhere.

This modifies nilfs_get_sb function to properly initialize the s_mode
member.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/super.c

@@ -1072,6 +1072,7 @@ nilfs_get_sb(struct file_system_type *fs_type, int flags,
 
 		/* New superblock instance created */
 		s->s_flags = flags;
+		s->s_mode = mode;
 		strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
 		sb_set_blocksize(s, block_size(sd.bdev));