[PCMCIA] Prevent duplicate insertion events calling socket_insert()

Some socket hardware appears to "bounce" when a card is inserted - we
seem to receive more than one SS_DETECT event.  Unfortunately, this
causes us to initialise, setup the socket, and create the necessary
devices multiple times.

Fix this by ignoring card insertion events when we already know that
there is a card in the socket.

drivers/pcmcia/cs.c

@@ -816,7 +816,8 @@ static int pccardd(void *__skt)
 				if ((skt->state & SOCKET_PRESENT) &&
 				     !(status & SS_DETECT))
 					socket_shutdown(skt);
-				if (status & SS_DETECT)
+				if (!(skt->state & SOCKET_PRESENT) &&
+				    (status & SS_DETECT))
 					socket_insert(skt);
 			}
 			if (events & SS_BATDEAD)