Fix rare crash seen when dereferencing backgroundIcon[NONE].

Because backgroundIcon[] is not initialized by the ScreenRecoveryUI
constructor, it should be initialized explicitly to NULL in Init().

If it is not initialized, ScreenRecoveryUI::SetBackground() can fail
for the NONE icon because the NULL test can fail and junk will be
dereferenced.

Change-Id: I4e3738d2e241ed90df43c984fb41e0072933f50a
1 file changed