RDMA/bnxt_re: Remove incorrect return check from slow path

The commit 691eb7c6 ("RDMA/bnxt_re: handle command completions after
driver detect a timedout") introduced code resulting in below warning
issued by the smatch static checker.

        drivers/infiniband/hw/bnxt_re/qplib_rcfw.c:513 __bnxt_qplib_rcfw_send_message()
        warn: duplicate check 'rc' (previous on line 506)

Fix the warning by removing incorrect code block.

Fixes: 691eb7c6

 ("RDMA/bnxt_re: handle command completions after driver detect a timedout")
Link: https://lore.kernel.org/r/20230616061700.741769-1-kashyap.desai@broadcom.com
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>