drm/evdi: Fix possible OOB in evdi_gem_fault

BUG=b:287203840
TEST=Various boards including sarien and trogdor

Change-Id: I109172dba4d1143f3bb5bf0377f770022065e228
Signed-off-by: Łukasz Spintzyk <lukasz.spintzyk@synaptics.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4883469
Reviewed-by: Dominik Behr <dbehr@chromium.org>
1 file changed