net: mana: Use int to check the return value of mana_gd_poll_cq()

mana_gd_poll_cq() may return -1 if an overflow error is detected (this
should never happen unless there is a bug in the driver or the hardware).

Fix the type of the variable "comp_read" by using int rather than u32.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: ca9c54d ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microsoft/mana/hw_channel.c

@@ -283,7 +283,7 @@ static void mana_hwc_comp_event(void *ctx, struct gdma_queue *q_self)
 	struct hwc_rx_oob comp_data = {};
 	struct gdma_comp *completions;
 	struct hwc_cq *hwc_cq = ctx;
-	u32 comp_read, i;
+	int comp_read, i;
 
 	WARN_ON_ONCE(hwc_cq->gdma_cq != q_self);
 

drivers/net/ethernet/microsoft/mana/mana_en.c

@@ -1061,7 +1061,7 @@ static void mana_process_rx_cqe(struct mana_rxq *rxq, struct mana_cq *cq,
 static void mana_poll_rx_cq(struct mana_cq *cq)
 {
 	struct gdma_comp *comp = cq->gdma_comp_buf;
-	u32 comp_read, i;
+	int comp_read, i;
 
 	comp_read = mana_gd_poll_cq(cq->gdma_cq, comp, CQE_POLLING_BUFFER);
 	WARN_ON_ONCE(comp_read > CQE_POLLING_BUFFER);