cmd/cgo: remove duplicate entry from gofmtLineReplacer

CL 158457 added a duplicate entry for the ",\n" -> "," replacement to
gofmtLineReplacer. Remove the duplicate.

Change-Id: I17684fcd19cbc96fa7a7b53bf7c1a6382bf1114f
Reviewed-on: https://go-review.googlesource.com/c/158619
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/cmd/cgo/godefs.go

@@ -151,7 +151,6 @@ var gofmtLineReplacer = strings.NewReplacer(
 	"<\n", "<",
 	">\n", ">",
 	"=\n", "=",
-	",\n", ",",
 	"\n", ";",
 )