mm/hugetlbfs: fix for_each_hstate() loop in init_hugetlbfs_fs()

LTP memfd_create04 started failing for some huge page sizes
after v5.4-10135-gc3bfc5dd.

The problem is the check introduced to for_each_hstate() loop that
should skip default_hstate_idx.  Since it doesn't update 'i' counter,
all subsequent huge page sizes are skipped as well.

Fixes: 8fc312b3 ("mm/hugetlbfs: fix error handling when setting up mounts")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hugetlbfs/inode.c

@@ -1498,8 +1498,10 @@ static int __init init_hugetlbfs_fs(void)
 	/* other hstates are optional */
 	i = 0;
 	for_each_hstate(h) {
-		if (i == default_hstate_idx)
+		if (i == default_hstate_idx) {
+			i++;
 			continue;
+		}
 
 		mnt = mount_one_hugetlbfs(h);
 		if (IS_ERR(mnt))