AUDIT: Return correct result from audit_filter_rules()

When the task refcounting was added to audit_filter_rules() it became
more of a problem that this function was violating the 'only one 
return from each function' rule. In fixing it to use a variable to store 
'ret' I stupidly neglected to actually change the 'return 1;' at the 
end. This makes it not work very well.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>