backslash not needed

src/freedombone-utils-elixir

       echo "cd $INSTALL_DIR || exit 1";
       echo "erlang_package=$erlang_package";
       echo "wget https://packages.erlang-solutions.com/\$erlang_package";
-      echo "if [ ! -f \"\$INSTALL_DIR/\$erlang_package\" ]; then";
+      echo "if [ ! -f \"$INSTALL_DIR/\$erlang_package\" ]; then";
       echo '    exit 2';
       echo 'fi';
       echo "dpkg -i \$erlang_package"; } > "$rootdir/usr/bin/install_elixir"