mysql: use build_with_debug() helper function

packages/databases/mysql/package.mk

@@ -55,7 +55,7 @@ PKG_CMAKE_OPTS_HOST="-DCMAKE_BUILD_TYPE=Release \
                      -DWITH_UNIT_TESTS=OFF \
                      -DWITH_ZLIB=bundled"
 
-if [ "$DEBUG" = yes -a "$TARGET_ARCH" = aarch64 ]; then
+if build_with_debug && [ "$TARGET_ARCH" = aarch64 ]; then
   pre_configure_target() {
     strip_lto
   }