Local backend: Disable individual channels when closing device
Local backend: Disable individual channels when closing device

Since only one application can open a given device at the same time,
this shouldn't have any side effect.

Signed-off-by: Paul Cercueil <73d292422978d45c9eeef455bb1b24a0db453722@analog.com>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio