totemsrp: Fix typo with cont gather

Patch f3ffd3da5c71a10e1783a38e50bafc61192854f6 introduced named states
of state-machine, but sadly contains logical problem causing
stats.continuous_gather increasing even when it shouldn't. Problem is
not critical, because continuous_gather is set to 0 on successful
membership creation.

Signed-off-by: Jan Friesse <jfriesse@redhat.com>
Reviewed-by: Christine Caulfield <ccaulfie@redhat.com>