staging: rdma: add a blank line after function

Fixed warnings found by checkpatch.pl:

Please use a blank line after function/struct/union/enum declarations
  FILE: drivers/staging/rdma/amso1100/c2_mq.c:158:
  FILE: drivers/staging/rdma/hfi1/file_ops.c:2069:
  FILE: drivers/staging/rdma/hfi1/sdma.c:744:
  FILE: drivers/staging/rdma/hfi1/verbs.c:1202:

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>