Fix BrokenPipeError in SpiceRecordWrapper.close()

If spice-record exits for whatever reason, the wrapper will get a
BrokenPipeError when trying to write to the stdin pipe. We simply ignore
this error, as we will later check the exit status in wait().

spicerecord/wrapper.py

@@ -59,8 +59,12 @@ def __exit__(self, *exc_info):
     def stop(self):
         if self.stopped:
             raise Exception("stop() already called")
-        self.p.stdin.write(b'Q\n')
-        self.p.stdin.close()
+        try:
+            self.p.stdin.write(b'Q\n')
+            self.p.stdin.close()
+        except (BrokenPipeError, IOError):
+            # The process has already exited
+            pass
         self.stopped = True
 
     def wait(self):