RDMA/vmw_pvrdma: Remove unnecessary check on wr->opcode

wr->opcode is unsigned; checking if it is negative is unnecessary. Fix
this issue by removing the check.

Fixes: 29c8d9eb ("IB: Add vmw_pvrdma driver")
Link: https://lore.kernel.org/r/20230605183728.47021-1-bryantan@vmware.com


Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/07c48eee-0aca-48ee-897a-38588c341c41@kili.mountain


Signed-off-by: Bryan Tan <bryantan@vmware.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>