pimd: Remove redundant logging

pimd: Remove redundant logging

When receiving a JOIN/PRUNE message if we have trace
turned on we output this:

2016/11/28 17:11:46.368827 PIM: pim_socket_recvfromto: HAVE_IP_PKTINFO to=224.0.0.13,103
2016/11/28 17:11:46.368956 PIM: Recv PIM JOINPRUNE packet from 169.254.0.6 to 224.0.0.13 on swp31s1: ttl=255 pim_version=2 pim_msg_size=34 checksum=e623
2016/11/28 17:11:46.369003 PIM: pim_joinprune_recv: from 169.254.0.6 on swp31s1
2016/11/28 17:11:46.369053 PIM: recv_prune: prune (S,G)=(20.0.11.253,229.1.2.3) rpt=0 wc=0 upstream=169.254.0.5 holdtime=210 from 169.254.0.6 on swp31s1
2016/11/28 17:11:46.369099 PIM: nonlocal_upstream: recv prune (S,G)=(20.0.11.253,229.1.2.3) to local upstream=169.254.0.5 on swp31s1

Clean up the messaging to this:

2016/11/28 17:11:46.368956 PIM: Recv PIM JOINPRUNE packet from 169.254.0.6 to 224.0.0.13 on swp31s1: ttl=255 pim_version=2 pim_msg_size=34 checksum=e623
2016/11/28 17:11:46.369053 PIM: recv_prune: prune (S,G)=(20.0.11.253,229.1.2.3) rpt=0 wc=0 upstream=169.254.0.5 holdtime=210 from 169.254.0.6 on swp31s1

Ticket: CM-13752
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Don Slice <dslice@cumulusnetworks.com>