Use try/finally instead of a nested handler

Author: deadlovelll

Lib/asyncio/unix_events.py

@@ -876,18 +876,17 @@ def _do_wait(self, pid, pidfd, callback, args):
         loop = events.get_running_loop()
         loop._remove_reader(pidfd)
         try:
-            try:
-                _, status = os.waitpid(pid, 0)
-            except ChildProcessError:
-                # The child process is already reaped
-                # (may happen if waitpid() is called elsewhere).
-                returncode = 255
-                logger.warning(
-                    "child process pid %d exit status already read: "
-                    " will report returncode 255",
-                    pid)
-            else:
-                returncode = waitstatus_to_exitcode(status)
+            _, status = os.waitpid(pid, 0)
+        except ChildProcessError:
+            # The child process is already reaped
+            # (may happen if waitpid() is called elsewhere).
+            returncode = 255
+            logger.warning(
+                "child process pid %d exit status already read: "
+                " will report returncode 255",
+                pid)
+        else:
+            returncode = waitstatus_to_exitcode(status)
         finally:
             os.close(pidfd)
         callback(pid, returncode, *args)