net: sockets: Explicitly flush conn/pkt queue on close()
net: sockets: Explicitly flush conn/pkt queue on close()

If a socket is closed without reading all data from peer or accepting
all pending connection, they will be leaked. So, flush queues
explicitly.

Signed-off-by: Paul Sokolovsky <35cb557f011771c94f127d6fef99f804b62203f5@linaro.org>

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