Don't do capabilities checks in bp_core_process_spammer_status()

These inline checks prevent the function from being used programmatically, such
as during a cron job. Instead, we move the cap checks up to the controller
"action" functions.

Fixes #5233

git-svn-id: https://buddypress.svn.wordpress.org/trunk@7562 cdf35c40-ae34-48e0-9cc9-0c9da1808c22