gigaset: prune use of tty_buffer_request_room

Calling tty_buffer_request_room() before tty_insert_flip_string() is unnecessary, costs CPU and for big buffers can mess up the multi-page allocation avoidance.

---
Note to -stable: applies correctly to 2.6.33 with fuzz 2.

 drivers/isdn/gigaset/interface.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

index a1bcbc2..f0dc6c9 100644
@@ -628,7 +628,6 @@ void gigaset_if_receive(struct cardstate *cs,
 	if (tty == NULL)
 		gig_dbg(DEBUG_IF, "receive on closed device");
 	else {
-		tty_buffer_request_room(tty, len);
 		tty_insert_flip_string(tty, buffer, len);
 		tty_flip_buffer_push(tty);
 	}