rest_router: Ensure that usage of icmp.dest_unreach and icmp.TimeExceeded complies with RFC 4884
rest_router: Ensure that usage of icmp.dest_unreach and icmp.TimeExceeded complies with RFC 4884

When using the icmp.dest_unreach and icmp.TimeExceeded classes, we
should ensure that it is in compliance with RFC 4884.  As such, the
data_len parameter passed to the constructor of each should be
interpreted in 32 bit units.  Furthermore - any data that is passed in
must be zero padded to a 32 bit boundary.

The only sample application known to use either of these types is rest_router.
This patch corrects its use of these classes.

Signed-off-by: Victor J. Orlikowski <72c670095bbd38b67036897d6da3425e0645f984@duke.edu>
Signed-off-by: FUJITA Tomonori <93dac1fe9c4b2a3957982200319981492ad4976e@lab.ntt.co.jp>

lagopus/ryu-lagopus-ext,hisaharu/ryu,takahashiminoru/ryu,zangree/ryu,habibiefaried/ryu,habibiefaried/ryu,gareging/SDN_Framework,lagopus/ryu-lagopus-ext,osrg/ryu,habibiefaried/ryu,shinpeimuraoka/ryu,fkakuma/ryu,alanquillin/ryu,Tejas-Subramanya/RYU_MEC,TakeshiTseng/ryu,iwaseyusuke/ryu,alanquillin/ryu,shinpeimuraoka/ryu,Tejas-Subramanya/RYU_MEC,fujita/ryu,iwaseyusuke/ryu,alanquillin/ryu,TakeshiTseng/ryu,fujita/ryu,lagopus/ryu-lagopus-ext,fkakuma/ryu,fkakuma/ryu,lagopus/ryu-lagopus-ext,osrg/ryu,iwaseyusuke/ryu,iwaseyusuke/ryu,osrg/ryu,pichuang/ryu,alanquillin/ryu,Tejas-Subramanya/RYU_MEC,pichuang/ryu,fkakuma/ryu,zangree/ryu,hisaharu/ryu,zangree/ryu,TakeshiTseng/ryu,Tejas-Subramanya/RYU_MEC,fujita/ryu,osrg/ryu,hisaharu/ryu,gareging/SDN_Framework,TakeshiTseng/ryu,shinpeimuraoka/ryu,takahashiminoru/ryu,gareging/SDN_Framework,pichuang/ryu,pichuang/ryu,alanquillin/ryu,gareging/SDN_Framework,hisaharu/ryu,gareging/SDN_Framework,osrg/ryu,shinpeimuraoka/ryu,pichuang/ryu,fujita/ryu,zangree/ryu,lagopus/ryu-lagopus-ext,iwaseyusuke/ryu,takahashiminoru/ryu,takahashiminoru/ryu,habibiefaried/ryu,takahashiminoru/ryu,fkakuma/ryu,zangree/ryu,shinpeimuraoka/ryu,hisaharu/ryu,TakeshiTseng/ryu,fujita/ryu,Tejas-Subramanya/RYU_MEC,habibiefaried/ryu