ipc-server: minor code cleanup
ipc-server: minor code cleanup

No logic change here, this one is mostly to please static analyzer:
 - client->fd can never be -1 (and if it could, close() a few lines below
would have needed the same check)
 - we never send permission denied error (dead code)

taiyu-len/sway,1ace/sway,1ace/sway,taiyu-len/sway,ascent12/sway,SirCmpwn/sway,ascent12/sway,ascent12/sway,1ace/sway,taiyu-len/sway