pimd: fix OIL not removed after IGMP prune

pimd: fix OIL not removed after IGMP prune

Issue: Client1------LHR-----(int-1)RP(int-2)------client2
Client2 send IGMP join for group G.
Client1 send IGMP join for group G.
verify show ip mroute in RP, will have 2 OIL.
Client2 send IGMP leave.
Verify show ip mroute in RP, will still have 2.

Root cause: When RP receives IGMP join from client2, it creates
a (s,g) channel oil and add the interface int-2 into oil list and
set the flag PIM_OIF_FLAG_PROTO_IGMP to int-2
Client1 send IGMP join, LHR will send a (*,G) join to RP. RP will
add the interface int-1 into the oil list of (s,g) channel_oil and
will set the flag PIM_OIF_FLAG_PROTO_IGMP and PIM_OIF_FLAG_PROTO_PIM
to the int-1 and set PIM_OIF_FLAG_PROTO_PIM to int-2 as well. It is
happening because of the pim_upstream_inherited_olist_decide() and
forward_on() get all the oil and update the flag wrongly.
So now when client 2 sends IGMP prune, RP will not remove the int-2
from oil list since both PIM_OIF_FLAG_PROTO_PIM & PIM_OIF_FLAG_PROTO_IGMP
are set, it just unset the flag PIM_OIF_FLAG_PROTO_IGMP.

Fix: Introduced new flags in if_channel, PIM_IF_FLAG_MASK_PROTO_PIM
& PIM_IF_FLAG_MASK_PROTO_IGMP. If a if_channel is created because of
pim join or pim (s,g,rpt) prune received, then set the flag
PIM_IF_FLAG_MASK_PROTO_PIM. If a if_channel is created becuase of IGMP
join received, then set the flag PIM_IF_FLAG_MASK_PROTO_IGMP.
When an interface needs to be added into the oil list check if
PIM_IF_FLAG_MASK_PROTO_PIM or PIM_IF_FLAG_MASK_PROTO_IGMP is set, then
update oil flag accordingly.

Signed-off-by: Sarita Patra <saritap@vmware.com>