IB/rdmavt: Delete unused routine

This routine was obsoleted by the patch below.

Delete it.

Fixes: a2a074ef ("RDMA: Handle ucontext allocations by IB/core")
Link: https://lore.kernel.org/r/20200316210454.7753.94689.stgit@awfm-01.aw.intel.com


Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>