tend ltend: Handle "cannot hold commodity" consistently

Transferring commodities from tenders to targets continues with the
next tender when a target can't hold this kind of commodity.
Transferring them from targets to tenders fails (ltend) or stops
tending (tend) when a tender can't hold this kind of commodity.  Has
always been that way.

Change the latter to continue with the next tender.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

src/lib/commands/lten.c

@@ -92,7 +92,7 @@ ltend(void)
 	if (maxtender == 0) {
 	    pr("A %s cannot hold any %s\n",
 	       mchr[(int)tender.shp_type].m_name, ip->i_name);
-	    return RET_FAIL;
+	    continue;
 	}
 	if (!snxtitem(&targets, EF_LAND,
 		      player->argp[4], "Units to be tended? "))