CHROMIUM: mac80211: Abort bgscan when under load

CHROMIUM: mac80211: Abort bgscan when under load

Reapply a patch that causes the mac80211 module to abort background scans
when data is found in the tx buffer, rather than merely suspending the
scan.  This patch was previously applied to a previous kernel version,
and reworked by Ashok from Cozybit.

BUG=chromium-os:31435
TEST=Reran network_WiFiMatFunc.090_BgScanAbort, hand tested patched img
Signed-off-by: Christopher Wiley <wiley@chromium.org>
Change-Id: I670ad51c0b9ceb10071175df01de3f141b5e43d3
Reviewed-on: https://gerrit.chromium.org/gerrit/26716