sysv: do not mark superblock dirty on mount

I did not find any docs about this file-system, and I have no possibility
to test my changes. Thus, this is untested.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/sysv/super.c

@@ -347,7 +347,6 @@ static int complete_read_super(struct super_block *sb, int silent, int size)
 		sb->s_flags |= MS_RDONLY;
 	if (sbi->s_truncate)
 		sb->s_root->d_op = &sysv_dentry_operations;
-	sb->s_dirt = 1;
 	return 1;
 }