sam: fix memory leak

sys/src/cmd/sam/error.c

@@ -138,7 +138,7 @@ termwrite(char *s)
 		else
 			Strinsert(&cmdstr, p, cmdstr.n);
 		cmdptadv += p->n;
-		free(p);
+		freetmpstr(p);
 	}else
 		Write(2, s, strlen(s));
 }

sys/src/cmd/sam/plan9.c

@@ -136,10 +136,10 @@ emalloc(ulong n)
 {
 	void *p;
 
-	p = malloc(n);
+	p = mallocz(n, 1);
 	if(p == 0)
 		panic("malloc fails");
-	memset(p, 0, n);
+	setmalloctag(p, getcallerpc(&n));
 	return p;
 }
 
@@ -149,5 +149,6 @@ erealloc(void *p, ulong n)
 	p = realloc(p, n);
 	if(p == 0)
 		panic("realloc fails");
+	setmalloctag(p, getcallerpc(&p));
 	return p;
 }