drivers: usb: fsl: Return if USB_MAX_CONTROLLER_COUNT is incorrect

Return if USB_MAX_CONTROLLER_COUNT hence the index of the controller
to be initialised is incorrect

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 5fd618d..97b7f14 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -76,7 +76,7 @@
 		break;
 	default:
 		printf("ERROR: wrong controller index!!\n");
-		break;
+		return -EINVAL;
 	};
 
 	*hccr = (struct ehci_hccr *)((uint32_t)&ehci->caplength);