net: ena: use explicit variable size for clarity

Use u64 instead of unsigned long long for clarity
Signed-off-by: Shai Brandes <shaibran@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amazon/ena/ena_com.c

@@ -2003,7 +2003,7 @@ void ena_com_aenq_intr_handler(struct ena_com_dev *dev, void *data)
 	struct ena_admin_aenq_entry *aenq_e;
 	struct ena_admin_aenq_common_desc *aenq_common;
 	struct ena_com_aenq *aenq  = &dev->aenq;
-	unsigned long long timestamp;
+	u64 timestamp;
 	ena_aenq_handler handler_cb;
 	u16 masked_head, processed = 0;
 	u8 phase;
@@ -2021,9 +2021,8 @@ void ena_com_aenq_intr_handler(struct ena_com_dev *dev, void *data)
 		 */
 		dma_rmb();
 
-		timestamp =
-			(unsigned long long)aenq_common->timestamp_low |
-			((unsigned long long)aenq_common->timestamp_high << 32);
+		timestamp = (u64)aenq_common->timestamp_low |
+			    ((u64)aenq_common->timestamp_high << 32);
 		pr_debug("AENQ! Group[%x] Syndrom[%x] timestamp: [%llus]\n",
 			 aenq_common->group, aenq_common->syndrom, timestamp);