nvme-pci: fix var. type for increasing cq_head

nvmeq->cq_head is compared with nvmeq->q_depth and changed the value
and cq_phase for handling the next cq db.

but, nvmeq->q_depth's type is u32 and max. value is 0x10000 when
CQP.MSQE is 0xffff and io_queue_depth is 0x10000.

current temp. variable for comparing with nvmeq->q_depth is overflowed
when previous nvmeq->cq_head is 0xffff.

in this case, nvmeq->cq_phase is not updated.
so, fix data type for temp. variable to u32.
Signed-off-by: JK Kim <jongkang.kim2@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -1032,7 +1032,7 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
 
 static inline void nvme_update_cq_head(struct nvme_queue *nvmeq)
 {
-	u16 tmp = nvmeq->cq_head + 1;
+	u32 tmp = nvmeq->cq_head + 1;
 
 	if (tmp == nvmeq->q_depth) {
 		nvmeq->cq_head = 0;