classes/insane: remove la2 check which no longer exists from ERROR_QA

classes/insane: remove la2 check which no longer exists from ERROR_QA

This check was actually removed a very long time ago in
6656381714c5956f71ca634f5a5f4aa4661bbf7e, before we even changed the QA
checks to use names instead of numbers - the name was probably added
ERROR_QA mistakenly because it hadn't also been removed from the comment
listing the QA checks or the function that determined which ones were
errors.

(From OE-Core rev: ff65497cd9a96d5ab49b16ba1f7e30a216ff4a42)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>