drivers: can: sam0: remove unused variable

Remove unused variable (only ever assigned) from the Atmel SAM0 CAN driver.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
diff --git a/drivers/can/can_sam0.c b/drivers/can/can_sam0.c
index 2f9a390..fbc2590 100644
--- a/drivers/can/can_sam0.c
+++ b/drivers/can/can_sam0.c
@@ -45,7 +45,6 @@
 {
 	const struct can_mcan_config *mcan_config = dev->config;
 	const struct can_sam0_config *sam_config = mcan_config->custom;
-	uint32_t bits = 0U;
 
 	switch (reg) {
 	case CAN_MCAN_ILS:
@@ -58,7 +57,6 @@
 		break;
 	default:
 		/* No field remap needed */
-		bits = val;
 		break;
 	};