tests: rename client_create to create_client_and_test_surface

A more descriptive name to not be confused with create_client().

v2: Rebased: fix also devices-test.c.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Marek Chalupa <mchqwerty@gmail.com>
diff --git a/tests/button-test.c b/tests/button-test.c
index 7959fb7..de84190 100644
--- a/tests/button-test.c
+++ b/tests/button-test.c
@@ -31,7 +31,7 @@
 	struct client *client;
 	struct pointer *pointer;
 
-	client = client_create(100, 100, 100, 100);
+	client = create_client_and_test_surface(100, 100, 100, 100);
 	assert(client);
 
 	pointer = client->input->pointer;