dispatch: don't clamp the range of the exit code twice

We already limit the range to (0, 255) in the call to sys.exit(). The
duplicated operation can't possibly be hurting us, but let's clean it up
to avoid confusion.

mercurial/dispatch.py

@@ -85,7 +85,7 b' def run():'
     req = request(pycompat.sysargv[1:])
     err = None
     try:
-        status = (dispatch(req) or 0) & 255
+        status = (dispatch(req) or 0)
     except error.StdioError as e:
         err = e
         status = -1