[docs] db_path variable in Cuttlefish-for-non-node_package-users [JIRA: RIAK-2037]

[marianoguerra]

in this page https://github.com/basho/cuttlefish/wiki/Cuttlefish-for-non-node_package-users there's this line:

 if CUTTLEFISH_CONFIG=$($RUNNER_BASE_DIR/bin/cuttlefish -e $RUNNER_ETC_DIR -d {{db_path}}/generated.configs -s $RUNNER_BASE_DIR/share/schema/ -c $RUNNER_ETC_DIR/{{cuttlefish_conf}})

which contains this part:

{{db_path}}/generated.configs

it seems to come from a copy paste from riak or a db project? maybe something like

$RUNNER_BASE_DIR/generated.configs

is a good replacement?