net: context: Fixing bug in net context put flow
net: context: Fixing bug in net context put flow

Following flow does not work:
net_context_get
net_context_bind
..
..
net_context_put
net_context_get
net_context_bind

At instance of call to net_context_bind, conn_handler
is not NULL and returns with EISCONN.

This patch sets conn_handler to NULL in net_context_unref

Change-Id: I56a50839101b22161644b3cd7c5f510fa1abae3e
Signed-off-by: Mitul Shah <64edfd6d756ba708b8622c90be9377d82d11f411@intel.com>

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