exit flashing scripts with error if no pandas

board/flash.py

@@ -15,3 +15,4 @@ if __name__ == "__main__":
     print("flashing", s)
     with Panda(serial=s) as p:
       p.flash()
+  exit(1 if len(serials) == 0 else 0)

board/jungle/flash.py

@@ -15,3 +15,5 @@ if __name__ == "__main__":
     print("flashing", s)
     with PandaJungle(serial=s) as p:
       p.flash()
+
+  exit(1 if len(serials) == 0 else 0)

board/jungle/recover.py

@@ -24,3 +24,4 @@ if __name__ == "__main__":
   for s in dfu_serials:
     print("flashing", s)
     PandaJungleDFU(s).recover()
+  exit(1 if len(dfu_serials) == 0 else 0)

board/recover.py

@@ -24,3 +24,4 @@ if __name__ == "__main__":
   for s in dfu_serials:
     print("flashing", s)
     PandaDFU(s).recover()
+  exit(1 if len(dfu_serials) == 0 else 0)