unix: simplify return statements.

mitogen/unix.py

@@ -50,8 +50,7 @@ def is_path_dead(path):
     try:
         s.connect(path)
     except socket.error, e:
-        if e[0] in (errno.ECONNREFUSED, errno.ENOENT):
+        return e[0] in (errno.ECONNREFUSED, errno.ENOENT)
-            return True
     return False