RDMA: Remove minor pahole differences between 32/64

To help automatic detection we want pahole to report the same struct
layouts for 32 and 64 bit compiles. These cases are all implicit
padding added at the end of embedded structs as part of a union.

The added reserved fields have no impact on the ABI.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

include/uapi/rdma/rdma_user_rxe.h

@@ -78,12 +78,14 @@ struct rxe_send_wr {
 		struct {
 			__u64	remote_addr;
 			__u32	rkey;
+			__u32	reserved;
 		} rdma;
 		struct {
 			__u64	remote_addr;
 			__u64	compare_add;
 			__u64	swap;
 			__u32	rkey;
+			__u32	reserved;
 		} atomic;
 		struct {
 			__u32	remote_qpn;

include/uapi/rdma/vmw_pvrdma-abi.h

@@ -262,6 +262,7 @@ struct pvrdma_sq_wqe_hdr {
 			__u32 length;
 			__u32 access_flags;
 			__u32 rkey;
+			__u32 reserved;
 		} fast_reg;
 		struct {
 			__u32 remote_qpn;