btrfs: remove useless ACL check

posix_acl_xattr_set() already does the check, and it's the only
way to feed in an ACL from userspace.
So the check here is useless, remove it.
Signed-off-by: zhang zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/acl.c

@@ -79,13 +79,6 @@ static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
 	const char *name;
 	char *value = NULL;
 
-	if (acl) {
-		ret = posix_acl_valid(acl);
-		if (ret < 0)
-			return ret;
-		ret = 0;
-	}
-
 	switch (type) {
 	case ACL_TYPE_ACCESS:
 		name = POSIX_ACL_XATTR_ACCESS;