ib_pack.h: Fix commentary IBA reference for CNP in IB opcode enum

IBA spec is now 1.3 not 3.1 and vol 1 should be mentioned
as there is also vol 2.
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

include/rdma/ib_pack.h

@@ -76,7 +76,7 @@ enum {
 	IB_OPCODE_UC                                = 0x20,
 	IB_OPCODE_RD                                = 0x40,
 	IB_OPCODE_UD                                = 0x60,
-	/* per IBTA 3.1 Table 38, A10.3.2 */
+	/* per IBTA 1.3 vol 1 Table 38, A10.3.2 */
 	IB_OPCODE_CNP                               = 0x80,
 
 	/* operations -- just used to define real constants */