Update language to comply with Android's inclusive language guidance

More details in: https://source.android.com/setup/contribute/respectful-code

Bug: 161896447
Test: build, run unittests
Change-Id: I6a7136b01ecce948a3997c60b7dcec848331e8ef
diff --git a/scripts/brillo_update_payload b/scripts/brillo_update_payload
index 4b581fb..9bae74e 100755
--- a/scripts/brillo_update_payload
+++ b/scripts/brillo_update_payload
@@ -896,7 +896,7 @@
   check_update_payload ${PAYCHECK_ARGS[@]} --check
 }
 
-# Sanity check that the real generator exists:
+# Check that the real generator exists:
 [[ -x "${GENERATOR}" ]] || GENERATOR="$(which delta_generator || true)"
 [[ -x "${GENERATOR}" ]] || die "can't find delta_generator"