cmd/internal/obj: stay consistent by defining loop variable outside loop header

Change-Id: Ieb0ae01cf393c4983e809ce95fedeaa854d19a99
GitHub-Last-Rev: 908f7565183c1cd19a3fbc47f406d53ad388fb97
GitHub-Pull-Request: golang/go#30004
Reviewed-on: https://go-review.googlesource.com/c/160428
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/internal/obj/objfile.go

@@ -252,7 +252,7 @@ func (w *objWriter) writeSymDebug(s *LSym) {
 	for i := 0; i < len(s.P); i += 16 {
 		fmt.Fprintf(ctxt.Bso, "\t%#04x", uint(i))
 		j := i
-		for j = i; j < i+16 && j < len(s.P); j++ {
+		for ; j < i+16 && j < len(s.P); j++ {
 			fmt.Fprintf(ctxt.Bso, " %02x", s.P[j])
 		}
 		for ; j < i+16; j++ {