sctp: sctp_output.c failed to compile when VLIB_BUFFER_TRACE_TRAJECTORY is enabled
sctp: sctp_output.c failed to compile when VLIB_BUFFER_TRACE_TRAJECTORY is enabled

Fixed a typo in sctp_push_header(). It was inherited from tcp_output.c

Change-Id: I810fcb4c24cfd3d54f15da72a5184cfc4df24592
Signed-off-by: Steven <a748ea44ad7b179c2313a856d44e1e4eb39869bb@cisco.com>

FDio/vpp,FDio/vpp,vpp-dev/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp,FDio/vpp,FDio/vpp,vpp-dev/vpp