ext4: don't warn about mnt_count if it has been disabled

Currently, if we mkfs a new ext4 volume with s_max_mnt_count set to
zero, and mount it for the first time, we will get the warning:

	maximal mount count reached, running e2fsck is recommended

It is really misleading. So change the check so that it won't warn in
that case.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/super.c

@@ -1914,7 +1914,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
 		ext4_msg(sb, KERN_WARNING,
 			 "warning: mounting fs with errors, "
 			 "running e2fsck is recommended");
-	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
+	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
 		 le16_to_cpu(es->s_mnt_count) >=
 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
 		ext4_msg(sb, KERN_WARNING,