IB/mad: Simplify SMI by eliminating smi_check_local_dr_smp()

IB/mad: Simplify SMI by eliminating smi_check_local_dr_smp()

The call to ib_get_agent_port() shouldn't be possible to fail when
smi_check_local_dr_smp() is called from ib_mad_recv_done_handler().
When it is called from handle_outgoing_dr_smp(), the device and
port_num come from mad_agent_priv so I assume the call to
ib_get_agent_port() shouldn't fail either.  In either case,
smi_check_local_smp() only uses the mad_agent pointer to check that
mad_agent->device->process_mad is not NULL.  The device pointer would
have to be the same as the one passed to smi_check_local_dr_smp()
since that pointer is used later instead of the one checked in
smi_check_local_smp().

Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>