RDMA/core: Clean up tracepoint headers

There's no need for core/trace.c to include rdma/ib_verbs.h twice.

Link: https://lore.kernel.org/r/20200702141946.3775.51943.stgit@klimt.1015granger.net


Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>