hw/arm_l2x0: Use LOG_GUEST_ERROR

Use LOG_GUEST_ERROR to report bad guest accesses.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/arm_l2x0.c

@@ -87,7 +87,8 @@ static uint64_t l2x0_priv_read(void *opaque, hwaddr offset,
     case 0xF80:
         return 0;
     default:
-        fprintf(stderr, "l2x0_priv_read: Bad offset %x\n", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "l2x0_priv_read: Bad offset %x\n", (int)offset);
         break;
     }
     return 0;
@@ -128,7 +129,8 @@ static void l2x0_priv_write(void *opaque, hwaddr offset,
     case 0xF80:
         return;
     default:
-        fprintf(stderr, "l2x0_priv_write: Bad offset %x\n", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "l2x0_priv_write: Bad offset %x\n", (int)offset);
         break;
     }
 }