kill boilerplates around posix_acl_create_masq()

new helper: posix_acl_create(&acl, gfp, mode_p).  Replaces acl with
modified clone, on failure releases acl and replaces with NULL.
Returns 0 or -ve on error.  All callers of posix_acl_create_masq()
switched.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index de66691..77463dd 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -202,9 +202,9 @@
 
 	if (default_acl) {
 		error = -xfs_inherit_acl(inode, default_acl);
+		default_acl = NULL;
 		if (unlikely(error))
 			goto out_cleanup_inode;
-		posix_acl_release(default_acl);
 	}