Honor maxcores again.

Reference: /n/patches.lsub.org/patch/mpmaxcores
Date: Thu Jul 12 15:01:59 CES 2012
Signed-off-by: paurea@lsub.org

--- /sys/src/nix/k10/mp.c	Tue Jul 10 14:41:49 2012
+++ /sys/src/nix/k10/mp.c	Thu Jul 12 15:00:54 2012
@@ -203,8 +203,10 @@
 		 */
 		DBG("mpparse: cpu %d pa %#ux bp %d\n",
 			p[1], l32get(pcmp->apicpa), p[3] & 0x02);
-		if((p[3] & 0x01) != 0 && maxcores-- > 0)
-			apicinit(p[1], l32get(pcmp->apicpa), p[3] & 0x02);
+		if((p[3] & 0x01) != 0 && maxcores > 0){
+				maxcores--;
+				apicinit(p[1], l32get(pcmp->apicpa), p[3] & 0x02);
+		}
 		p += 20;
 		break;
 	case 1:					/* bus */