(_krb5_xlock): fix compile error in last commit

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@13196 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/krb5/fcache.c

@@ -90,7 +90,7 @@ _krb5_xlock(krb5_context context, int fd, krb5_boolean exclusive,
 			      filename);
     else if(ret != 0)
 	krb5_set_error_string(context, "error locking cache file %s: %s",
-			      filename);
+			      filename, strerror(ret));
     return ret;
 }