reass frag_n should to be inited to 0
reass frag_n should to be inited to 0

Change-Id: I8a4a7a85e86acbfe411e6dfa22e3976d7d4c903b
Signed-off-by: ahdj007 <1b774497373669e00e0aec18f4d97e19aaab3049@zte.com.cn>

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