Fix firmware copying in distrib script

Author: facchinm

distrib.sh

@@ -20,7 +20,7 @@ GOOS=windows GOARCH=386 GO386=387 go build -o distrib/windows/updater.exe github
 # need osxcross in path
 GOOS=darwin GOARCH=amd64 go build -o distrib/osx/updater github.com/arduino-libraries/FirmwareUpdater/cli
 
-cp -r firmwares distrib/
+cp -r $GOPATH/src/github.com/arduino-libraries/FirmwareUpdater/firmwares distrib/
 
 # call the tool with something like
 # ./linux64/updater -flasher firmwares/NINA/FirmwareUpdater.mkrwifi1010.ino.bin -firmware firmwares/NINA/1.2.1/NINA_W102.bin -port /dev/ttyACM0  -address arduino.cc:443 -restore_binary /tmp/arduino_build_619137/WiFiSSLClient.ino.bin -programmer {runtime.tools.bossac}/bossac