net: ipv6: net_ipv6_create() should know about TCP
net: ipv6: net_ipv6_create() should know about TCP

This fixes the following build warning:
	net/yaip/ipv6.c:333:9: warning: 'nexthdr' is used unin-
		itialized in this function [-Wuninitialized]

This relies on net_context_get_ip_proto() providing the correct
protocol given a certain context.  Currently, it only returns either
TCP or UDP, which is sufficient for net_ipv6_create().  However, enum
net_ip_protocol contains other unhandled protocols (ICMP and ICMPv6,
respectively), which might or might not need to be handled in the
future.

Change-Id: I1f7af54612c3e1c978e734fc0e6b2ff1a61089f8
Signed-off-by: Leandro Pereira <51c7437a02b34df685e6b4ecb2e9bca23efe2e1a@intel.com>

bigdinotech/zephyr,explora26/zephyr,tidyjiang8/zephyr-doc,punitvara/zephyr,galak/zephyr,nashif/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,erwango/zephyr,zephyriot/zephyr,fbsder/zephyr,ldts/zephyr,bboozzoo/zephyr,tidyjiang8/zephyr-doc,runchip/zephyr-cc3200,Vudentz/zephyr,nashif/zephyr,rsalveti/zephyr,bboozzoo/zephyr,mbolivar/zephyr,erwango/zephyr,Vudentz/zephyr,erwango/zephyr,sharronliu/zephyr,pklazy/zephyr,aceofall/zephyr-iotos,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,fbsder/zephyr,fbsder/zephyr,sharronliu/zephyr,finikorg/zephyr,rsalveti/zephyr,fbsder/zephyr,holtmann/zephyr,Vudentz/zephyr,Vudentz/zephyr,holtmann/zephyr,aceofall/zephyr-iotos,aceofall/zephyr-iotos,ldts/zephyr,erwango/zephyr,runchip/zephyr-cc3220,bigdinotech/zephyr,runchip/zephyr-cc3220,kraj/zephyr,tidyjiang8/zephyr-doc,aceofall/zephyr-iotos,mbolivar/zephyr,rsalveti/zephyr,bboozzoo/zephyr,runchip/zephyr-cc3200,fractalclone/zephyr-riscv,erwango/zephyr,bboozzoo/zephyr,fbsder/zephyr,aceofall/zephyr-iotos,finikorg/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,bigdinotech/zephyr,sharronliu/zephyr,runchip/zephyr-cc3200,ldts/zephyr,explora26/zephyr,finikorg/zephyr,sharronliu/zephyr,zephyriot/zephyr,punitvara/zephyr,runchip/zephyr-cc3200,zephyrproject-rtos/zephyr,punitvara/zephyr,pklazy/zephyr,pklazy/zephyr,tidyjiang8/zephyr-doc,holtmann/zephyr,rsalveti/zephyr,mbolivar/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,fractalclone/zephyr-riscv,kraj/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,runchip/zephyr-cc3220,mbolivar/zephyr,pklazy/zephyr,pklazy/zephyr,holtmann/zephyr,kraj/zephyr,zephyriot/zephyr,zephyriot/zephyr,runchip/zephyr-cc3220,fractalclone/zephyr-riscv,runchip/zephyr-cc3200,kraj/zephyr,rsalveti/zephyr,galak/zephyr,nashif/zephyr,fractalclone/zephyr-riscv,finikorg/zephyr,zephyriot/zephyr,explora26/zephyr,galak/zephyr,galak/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,fractalclone/zephyr-riscv,GiulianoFranchetto/zephyr,sharronliu/zephyr,ldts/zephyr,runchip/zephyr-cc3220,galak/zephyr,bigdinotech/zephyr,bigdinotech/zephyr,ldts/zephyr,mbolivar/zephyr,holtmann/zephyr,tidyjiang8/zephyr-doc,nashif/zephyr,bboozzoo/zephyr