Remove usage of CHECK_NOTNULL

We want to switch to absl logging instead of glog.  gtest and ceres are
going there, and we already have absl as a dependency.  ABSL doesn't
have CHECK_NOTNULL, and we can move things over in an easier to review
fashion.

Change-Id: Ifd9a11ec34a2357cec43f88dba015db9c28ed2cf
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2022/localizer/localizer.cc b/y2022/localizer/localizer.cc
index ab91db3..c4ccf85 100644
--- a/y2022/localizer/localizer.cc
+++ b/y2022/localizer/localizer.cc
@@ -489,8 +489,8 @@
     const OldPosition &state,
     const frc971::vision::calibration::CameraCalibration *calibration,
     std::optional<RejectionReason> *rejection_reason) const {
-  CHECK_NOTNULL(rejection_reason);
-  CHECK_NOTNULL(calibration);
+  CHECK(rejection_reason != nullptr);
+  CHECK(calibration != nullptr);
   // Per the CameraCalibration specification, we can actually determine whether
   // the camera is the turret camera just from the presence of the
   // turret_extrinsics member.