RDMA/bnxt_re: Fix missing le16_to_cpu

RDMA/bnxt_re: Fix missing le16_to_cpu

From sparse:

drivers/infiniband/hw/bnxt_re/main.c:1274:18: warning: cast from restricted __le16
drivers/infiniband/hw/bnxt_re/main.c:1275:18: warning: cast from restricted __le16
drivers/infiniband/hw/bnxt_re/main.c:1276:18: warning: cast from restricted __le16
drivers/infiniband/hw/bnxt_re/main.c:1277:21: warning: restricted __le16 degrades to integer

Fixes: 2b827ea1926b ("RDMA/bnxt_re: Query HWRM Interface version from FW")
Link: https://lore.kernel.org/r/1574317343-23300-4-git-send-email-devesh.sharma@broadcom.com
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>