net/smc: Use sysctl-specified types of buffers in new link group

This patch introduces a new SMC-R specific element buf_type
in struct smc_link_group, for recording the value of sysctl
smcr_buf_type when link group is created.

New created link group will create and reuse buffers of the
type specified by buf_type.

Signed-off-by: Wen Gu <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/smc/smc_core.c

···
 		lgr->net = smc_ib_net(lnk->smcibdev);
 		lgr_list = &smc_lgr_list.list;
 		lgr_lock = &smc_lgr_list.lock;
+		lgr->buf_type = lgr->net->smc.sysctl_smcr_buf_type;
 		atomic_inc(&lgr_cnt);
 	}
 	smc->conn.lgr = lgr;

net/smc/smc_core.h

···
 						/* used rtoken elements */
 			u8			next_link_id;
 			enum smc_lgr_type	type;
+			enum smcr_buf_type	buf_type;
 						/* redundancy state */
 			u8			pnet_id[SMC_MAX_PNETID_LEN + 1];
 						/* pnet id of this lgr */