IB/{hfi1,qib}: Cleanup open coded sge sizing

Sge sizing is done in several places using an open coded method.

This can cause maintenance issues.  The open coded method is
encapsulated in a helper routine.  The helper was introduced with
commit:

1198fcea8a ("IB/hfi1, rdmavt: Move SGE state helper routines into
rdmavt")

Update all call sites that have the open coded path with the helper
routine.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/verbs.c

@@ -553,11 +553,7 @@ static noinline int build_verbs_ulp_payload(
 	int ret = 0;
 
 	while (length) {
-		len = ss->sge.length;
-		if (len > length)
-			len = length;
-		if (len > ss->sge.sge_length)
-			len = ss->sge.sge_length;
+		len = rvt_get_sge_length(&ss->sge, length);
 		WARN_ON_ONCE(len == 0);
 		ret = sdma_txadd_kvaddr(
 			sde->dd,
@@ -914,12 +910,8 @@ int hfi1_verbs_send_pio(struct rvt_qp *qp, struct hfi1_pkt_state *ps,
 		if (ss) {
 			while (len) {
 				void *addr = ss->sge.vaddr;
-				u32 slen = ss->sge.length;
+				u32 slen = rvt_get_sge_length(&ss->sge, len);
 
-				if (slen > len)
-					slen = len;
-				if (slen > ss->sge.sge_length)
-					slen = ss->sge.sge_length;
 				rvt_update_sge(ss, slen, false);
 				seg_pio_copy_mid(pbuf, addr, slen);
 				len -= slen;