delete all uses of panicln by rewriting them using panic or,
in the tests, println+panic.
gofmt some tests too.

R=rsc
CC=golang-dev
https://golang.org/cl/741041
diff --git a/test/mallocfin.go b/test/mallocfin.go
index 4c83258..918b806 100644
--- a/test/mallocfin.go
+++ b/test/mallocfin.go
@@ -27,14 +27,16 @@
 
 func finalA(a *A) {
 	if final[a.n] != 0 {
-		panicln("finalA", a.n, final[a.n])
+		println("finalA", a.n, final[a.n])
+		panic("fail")
 	}
 	final[a.n] = 1
 }
 
 func finalB(b *B) {
 	if final[b.n] != 1 {
-		panicln("finalB", b.n, final[b.n])
+		println("finalB", b.n, final[b.n])
+		panic("fail")
 	}
 	final[b.n] = 2
 	nfinal++