AP scan on correct wifi interfaces when dumping logs.

On some architectures (e.g. tegra2_seaboard), wifi interface does not
enumerate as 'wlan0'.  Therefore, first query flimflam for all known wifi
interfaces (not just 'wlan0') before doing AP scan.
Scanning on any potential additional interfaces is an added bonus
where applicable.

Change-Id: I9797acc98b36d8cb631e2a9afeb3bd16186e7b13

BUG=chromium-os:7000
TEST=Run a failing wifi test on x86-generic, "iw dev wlan0 scan" results should appear at end of test report; Run a failing wifi test on tegra2_seaboard, "iw dev eth0 scan" results should appear at end of test report.

Review URL: http://codereview.chromium.org/3441029
1 file changed