rds: Fix endianness annotations for RDS extension headers

Per the RDS 3.1 spec [1], RDS extension headers EXTHDR_NPATHS and
EXTHDR_GEN_NUM are be16 and be32 values respectively, exchanged during
normal operations over-the-wire (RDS Ping/Pong). This contrasts their
declarations as host endian unsigned ints.

Fix the annotations across occurrences. Flagged by Sparse.

[1] https://oss.oracle.com/projects/rds/dist/documentation/rds-3.1-spec.html

Signed-off-by: Ujwal Kundur <[e-mail]>
Reviewed-by: Allison Henderson <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/rds/message.c

···
 [RDS_EXTHDR_VERSION]	= sizeof(struct rds_ext_header_version),
 [RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
 [RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
-[RDS_EXTHDR_NPATHS]	= sizeof(u16),
-[RDS_EXTHDR_GEN_NUM]	= sizeof(u32),
+[RDS_EXTHDR_NPATHS]	= sizeof(__be16),
+[RDS_EXTHDR_GEN_NUM]	= sizeof(__be32),
 };
 
 void rds_message_addref(struct rds_message *rm)

net/rds/recv.c

···
 	unsigned int pos = 0, type, len;
 	union {
 		struct rds_ext_header_version version;
-		u16 rds_npaths;
-		u32 rds_gen_num;
+		__be16 rds_npaths;
+		__be32 rds_gen_num;
 	} buffer;
 	u32 new_peer_gen_num = 0;
 

net/rds/send.c

···
 
 	if (RDS_HS_PROBE(be16_to_cpu(sport), be16_to_cpu(dport)) &&
 	    cp->cp_conn->c_trans->t_mp_capable) {
-		u16 npaths = cpu_to_be16(RDS_MPATH_WORKERS);
-		u32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num);
+		__be16 npaths = cpu_to_be16(RDS_MPATH_WORKERS);
+		__be32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num);
 
 		rds_message_add_extension(&rm->m_inc.i_hdr,
 					  RDS_EXTHDR_NPATHS, &npaths,