Don't use typedefs that hide *s.

gr_surface was causing confusion for no good reason.

Change-Id: If7120187f9a00dd16297877fc49352185a4d4ea6
diff --git a/minui/graphics.cpp b/minui/graphics.cpp
index f240f4b..f09f1c6 100644
--- a/minui/graphics.cpp
+++ b/minui/graphics.cpp
@@ -326,7 +326,7 @@
         gr_clear();
 
         gr_color(255, 0, 0, 255);
-        gr_surface frame = images[x%frames];
+        GRSurface* frame = images[x%frames];
         gr_blit(frame, 0, 0, frame->width, frame->height, x, 0);
 
         gr_color(255, 0, 0, 128);