IB/qib: Decode path MTU optimization

Store both the encoded and decoded MTU in the QP structure as a minor
optimization for UC/RC receive routines.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/qib/qib_verbs.h b/drivers/infiniband/hw/qib/qib_verbs.h
index 95e5b47..ec3711f 100644
--- a/drivers/infiniband/hw/qib/qib_verbs.h
+++ b/drivers/infiniband/hw/qib/qib_verbs.h
@@ -485,6 +485,7 @@
 	u8 alt_timeout;         /* Alternate path timeout for this QP */
 	u8 port_num;
 	enum ib_mtu path_mtu;
+	u32 pmtu;		/* decoded from path_mtu */
 	u32 remote_qpn;
 	u32 qkey;               /* QKEY for this QP (for UD or RD) */
 	u32 s_size;             /* send work queue size */