The current implementation of rxe_check_bind_mw() in rxe_mw.c is incorrect
since it requires the new key portion provided by the mw consumer to be
different than the previous key portion. This is not required by the
IBA. Remove the test.

Link: https://lore.kernel.org/linux-rdma/fb4614e7-4cac-0dc7-3ef7-766dfd10e8f2@gmail.com/
Fixes: 32a577b4 ("Add support for bind MW work requests")
Link: https://lore.kernel.org/r/20220714204619.13396-1-rpearsonhpe@gmail.comSigned-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>