Fix below build error when feature WLAN_OBJMGR_REF_ID_TRACE
enabled:
1: "line_node" may be used without initialized in function
wlan_objmgr_trace_check_line. Fix by linking new
line node to link_head.
2: Use "peer_obj" to print trace info of peer object.
The "vdev_obj" is invalid when object type is WLAN_PEER_OP.
Change-Id: I067704976bb8d2dd11873af96fa4778adce7901b
CRs-Fixed: 2802642
cee83b8a96