cmd/objdump: Fix error logging

Change-Id: I6b1b4d3e8c039ba3198cb4b9765de75859ea8c32
Reviewed-on: https://go-review.googlesource.com/1214Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/objdump/main.go

@@ -80,7 +80,7 @@ func main() {
 
 	dis, err := f.Disasm()
 	if err != nil {
-		log.Fatal("disassemble %s: %v", flag.Arg(0), err)
+		log.Fatalf("disassemble %s: %v", flag.Arg(0), err)
 	}
 
 	switch flag.NArg() {