tests: use igt_assert/igt_require more

With the new _f variants we can replace almost all of them.

Also remove a ton of checks for argc != 1, they're a bit useless ...

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

tests/gem_exec_bad_domains.c

@@ -144,10 +144,7 @@ static void multi_write_domain(int fd)
 	gem_close(fd, handle);
 	gem_close(fd, handle_target);
 
-	if (ret == 0 || errno != EINVAL) {
-		fprintf(stderr, "multiple write domains not rejected\n");
-		igt_fail(1);
-	}
+	igt_assert(ret != 0 && errno == EINVAL);
 }
 
 int fd;