bitbake: server/process: Fix select call

There was a report that bitbake -e | less would use 100% cpu when it shouldn't
really. The issue appears to be a bogus file descriptor in the select call. We
shouldn't be blocking if there is event data pending to a *reader* from server
context.

[YOCTO #7138]

(Bitbake rev: 8f166e1a0f3574ae7d1e917a8bb403b87bad15bf)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/process.py

@@ -115,7 +115,7 @@ class ProcessServer(Process, BaseImplServer):
                     self.quitout.recv()
                     self.quit = True
 
-                self.idle_commands(.1, [self.event_queue._reader, self.command_channel, self.quitout])
+                self.idle_commands(.1, [self.command_channel, self.quitout])
             except Exception:
                 logger.exception('Running command %s', command)