b6ac5a8 nwfilter: change methods returning virNWFilterIPAddrLearnReq to use bool

Authored and Committed by berrange 6 years ago
    nwfilter: change methods returning virNWFilterIPAddrLearnReq to use bool
    
    Various methods return a virNWFilterIPAddrLearnReq struct, but the
    callers are only interested in whether the return value is non-NULL.
    It is thus preferrable to just return a bool.
    
    Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
    Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>