bcmdhd: Add checks for stack buffer overflows

These two checks prevent exploitable buffer overflows in two scenarios.
1. Long WPS_ID_DEVICE_NAME in WPS info elements
2. Invalid SSID determined in certain scan results

Bug: 27335848

[fixes CVE-2016-0801]
Signed-off-by: Kees Cook <keescook@chromium.org>
Change-Id: I2d7bc6c707c3d06f5a5ece9458c8731fe009ce52
1 file changed