dynamic_debug: simplify dynamic_debug_init error exit

We dont want errors while parsing ddebug_query to unload ddebug
tables, so set success after tables are loaded, and return 0 after
query parsing is done.

Simplify error handling code since its no longer used for success,
and change goto label to out_err to clarify this.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>