Refactor: tools: Some best practices in cli_resource_delete()

Use bool instead of gboolean. Remove elses after early returns. Make
node const. Improve variable names. Put all "if (nodes == NULL)" cases
into one block (for clarity at the expense of one level of nesting). Use
gpointer * instead of void **. Bring line lengths to <= 80.

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>