correct nix load average. noticed as part of gsoc converstation.

Reference: /n/atom/patch/applied/nixloadaverage
Date: Fri May 23 22:17:27 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/port/proc.c	Fri May 23 22:17:27 2014
+++ /sys/src/nix/port/proc.c	Fri May 23 22:17:27 2014
@@ -1676,8 +1676,7 @@
 	sch = m->sch;
 	p = m->proc;
 	if(p) {
-		if(m->machno == 0)
-			sch->nrun++;
+		sch->nrun++;
 		p->time[p->insyscall]++;
 	}