ixgbevf: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of just letting the code
fall through to the next case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c

@@ -2633,6 +2633,7 @@ static void ixgbevf_set_num_queues(struct ixgbevf_adapter *adapter)
 			adapter->num_rx_queues = rss;
 			adapter->num_tx_queues = rss;
 			adapter->num_xdp_queues = adapter->xdp_prog ? rss : 0;
+			break;
 		default:
 			break;
 		}