network: make use of the iio_context_pdata() helper
network: make use of the iio_context_pdata() helper

This tries to most of the access to the pdata pointer of the IIO context.

Signed-off-by: Alexandru Ardelean <685557f6b7c225d86b536740313ed51b24843a58@analog.com>

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