RDMA/rxe: Fix style warnings

Fixed several minor checkpatch warnings in existing rxe source.

Link: https://lore.kernel.org/r/20200820224638.3212-3-rpearson@hpe.com


Signed-off-by: Bob Pearson <rpearson@hpe.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>