.build/install-gtest: call the die function for consistency

Author: generalmimon

.build/install-gtest

@@ -44,9 +44,7 @@ case $cpp_standard in
 # least C++14, see https://github.com/google/googletest/releases/tag/v1.16.0
 gtest_version_tag=v1.16.0
 else
-echo "Error: unsupported value $1 of <cpp-standard>" >&2
-printf '\n%s\n' "$(usage)" >&2
-exit 1
+die "Error: unsupported value $1 of <cpp-standard>"
 fi
 ;;
 esac