Write logs to stderr by default

Minor refactoring to use the filePair struct for both init sock and log pipe

Co-authored-by: Julia Nedialkova <julianedialkova@hotmail.com>
Signed-off-by: Georgi Sabev <georgethebeatle@gmail.com>

main.go

@@ -87,7 +87,7 @@ func main() {
 		},
 		cli.StringFlag{
 			Name:  "log",
-			Value: "/dev/null",
+			Value: "/dev/stderr",
 			Usage: "set the log file path where internal debug information is written",
 		},
 		cli.StringFlag{