unix: single space after period in generated zptrace header

Fix the header in the generated zptrace*_linux.go files to consistently
use single space after a period.

Change-Id: I527f27a68e14bc103639b1dd5734ec06ae267e01
Reviewed-on: https://go-review.googlesource.com/73875
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

unix/linux/mkall.go

@@ -423,7 +423,7 @@ func generatePtracePair(arch1, arch2 string) error {
 		return err
 	}
 	buf := bufio.NewWriter(f)
-	fmt.Fprintf(buf, "// Code generated by linux/mkall.go generatePtracePair(%s, %s).  DO NOT EDIT.\n", arch1, arch2)
+	fmt.Fprintf(buf, "// Code generated by linux/mkall.go generatePtracePair(%s, %s). DO NOT EDIT.\n", arch1, arch2)
 	fmt.Fprintf(buf, "\n")
 	fmt.Fprintf(buf, "// +build linux\n")
 	fmt.Fprintf(buf, "// +build %s %s\n", arch1, arch2)

unix/zptrace386_linux.go

-// Code generated by linux/mkall.go generatePtracePair(386, amd64).  DO NOT EDIT.
+// Code generated by linux/mkall.go generatePtracePair(386, amd64). DO NOT EDIT.
 
 // +build linux
 // +build 386 amd64

unix/zptracearm_linux.go

-// Code generated by linux/mkall.go generatePtracePair(arm, arm64).  DO NOT EDIT.
+// Code generated by linux/mkall.go generatePtracePair(arm, arm64). DO NOT EDIT.
 
 // +build linux
 // +build arm arm64

unix/zptracemips_linux.go

-// Code generated by linux/mkall.go generatePtracePair(mips, mips64).  DO NOT EDIT.
+// Code generated by linux/mkall.go generatePtracePair(mips, mips64). DO NOT EDIT.
 
 // +build linux
 // +build mips mips64

unix/zptracemipsle_linux.go

-// Code generated by linux/mkall.go generatePtracePair(mipsle, mips64le).  DO NOT EDIT.
+// Code generated by linux/mkall.go generatePtracePair(mipsle, mips64le). DO NOT EDIT.
 
 // +build linux
 // +build mipsle mips64le