bgpd: The deletion of a bgp route does not need to send some data

bgpd: The deletion of a bgp route does not need to send some data

When sending a bgp route down to zebra for deletion, the
ZEBRA_FLAG_ALLOW_RECURSION and ZEBRA_FLAG_IBGP flags
are not needed in zebra.  So remove the setting
of the api.flags.  If we remove this data from being
passed down we no longer need the peer data structure.

Remove the lookup of the peer data structure and the setting
of the flags as that peer was NULL in some evpn symmetric
routing cases for shutdown of bgp.

Ticket: CM-20720
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>