IB/mad: Fix RMPP header RRespTime manipulation

Fix ib_set_rmpp_flags() to use the correct bit mask for RRespTime.  In
the 8-bit field of the RMPP header, the first 5 bits are RRespTime and
next 3 bits are RMPPFlags. Hence to retain the first 5 bits, the mask
should be 0xF8 instead of 0xF1.

ack_recv()-->format_ack() calls ib_set_rmpp_flags() and due to the
incorrect ANDing with 0xF1, RRespTime got changed incorrectly and RMPP
Acks sent back always had a RRespTime of 0x1E (30) which caused the
other end to consider the time outs to be approximately 4297 seconds
(i.e. in the order of 4*2^30) instead of the usual ~4 seconds (order
of 4*2^20).

Signed-off-by: Ramachandra K <ramachandra.kuchimanchi@qlogic.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>