remove sprint

Reference: /n/atom/patch/applied/nixdevarchnosprint
Date: Sun Aug 16 06:21:11 CES 2015
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/devarch.c	Sun Aug 16 06:21:02 2015
+++ /sys/src/nix/k10/devarch.c	Sun Aug 16 06:21:04 2015
@@ -226,7 +226,7 @@
 static long
 archread(Chan *c, void *a, long n, vlong offset)
 {
-	char *buf, *p;
+	char *buf, *p, *e;
 	int port;
 	u16int *sp;
 	u32int *lp;
@@ -276,6 +276,7 @@
 	if((buf = malloc(n)) == nil)
 		error(Enomem);
 	p = buf;
+	e = buf+n;
 	n = n/Linelen;
 	offset = offset/Linelen;
 
@@ -285,8 +286,7 @@
 		for(map = iomap.map; n > 0 && map != nil; map = map->next){
 			if(offset-- > 0)
 				continue;
-			sprint(p, "%#8ux %#8ux %-16.16s\n", map->start, map->end-1, map->tag);
-			p += Linelen;
+			p = seprint(p, e, "%#8ux %#8ux %-16.16s\n", map->start, map->end-1, map->tag);
 			n--;
 		}
 		unlock(&iomap);