net: ipv6: Verify ICMPv6 checksum before accepting packet
net: ipv6: Verify ICMPv6 checksum before accepting packet

Make sure that ICMPv6 checksum is correct before continuing
processing the packet.

Fixes #10971

Signed-off-by: Jukka Rissanen <f9f077d1da4c7aa947f9864fa5a28c3588f6a45d@linux.intel.com>

galak/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,galak/zephyr,punitvara/zephyr,punitvara/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,explora26/zephyr,explora26/zephyr,punitvara/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,ldts/zephyr,ldts/zephyr,finikorg/zephyr,ldts/zephyr,galak/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,ldts/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,explora26/zephyr,finikorg/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr,finikorg/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr