drm-tests: minor fixes for dumb_map

This change checks export failure, and close fd earlier to avoid leak on
later failures. Meanwhile, this change fixes some typos.

BUG=b:282243659
TEST=emerge-$BOARD drm-tests

Change-Id: I985eb527a3c3ab7295fb0520787e8da2c97436f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/drm-tests/+/4530680
Commit-Queue: Yiwei Zhang <zzyiwei@chromium.org>
Tested-by: Yiwei Zhang <zzyiwei@chromium.org>
Reviewed-by: Dawn Han <dawnhan@google.com>
Reviewed-by: Andres Calderon Jaramillo <andrescj@chromium.org>
1 file changed