IB: Remove __constant_{endian} uses

The base versions handle constant folding just fine, use them
directly.  The replacements are OK in the include/ files as they are
not exported to userspace so we don't need the __ prefixed versions.

This patch does not affect code generation at all.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/rdma/ib_mad.h b/include/rdma/ib_mad.h
index 5f6c40f..8cc71a1 100644
--- a/include/rdma/ib_mad.h
+++ b/include/rdma/ib_mad.h
@@ -107,7 +107,7 @@
 #define	IB_MGMT_RMPP_STATUS_ABORT_MAX		127
 
 #define IB_QP0		0
-#define IB_QP1		__constant_htonl(1)
+#define IB_QP1		cpu_to_be32(1)
 #define IB_QP1_QKEY	0x80010000
 #define IB_QP_SET_QKEY	0x80000000