Avoid compiler casting warnings Part 2

This saves instructions that are related to casting as well as compiler warnings.

lib/util/regress/tailq/hltq_test.c

@@ -201,5 +201,5 @@ main(int argc, char *argv[])
 	    getprogname(), ntests, errors, (ntests - errors) * 100 / ntests);
     }
 
-    exit(errors);
+    return errors;
 }