Merge pull request #3292 from jepler/allocate_display_bus_bug

allocate_display_bus: fix bug where in-use bus would be returned

Author: tannewt

shared-module/displayio/__init__.c

@@ -394,8 +394,8 @@ primary_display_t *allocate_display_or_raise(void) {
 }
 primary_display_t *allocate_display_bus(void) {
     for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
-        mp_const_obj_t display_type = displays[i].display.base.type;
-        if (display_type == NULL || display_type == &mp_type_NoneType) {
+        mp_const_obj_t display_bus_type = displays[i].bus_base.type;
+        if (display_bus_type == NULL || display_bus_type == &mp_type_NoneType) {
             return &displays[i];
         }
     }