ipw2200: batch non-user-requested scan result notifications

ipw2200: batch non-user-requested scan result notifications

patch 0b5316769774d1dc2fdd702e095f9e6992af269a in mainline.

ipw2200 makes extensive use of background scanning when unassociated or
down.  Unfortunately, the firmware sends scan completed events many
times per second, which the driver pushes directly up to userspace.
This needlessly wakes up processes listening for wireless events many
times per second.  Batch together scan completed events for
non-user-requested scans and send them up to userspace every 4 seconds.
Scan completed events resulting from an SIOCSIWSCAN call are pushed up
without delay.

Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: Tobias Powalowski <t.powa@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>