qcacld-3.0: Reset is_acs_allowed variable when chan count is 0
When world mode is set (ACS chan list is empty) and ACS request comes to
driver, is_acs_allowed variable is not reset. Due to this, in subsequent
ACS requests, is_acs_allowed variable would become 1, leading to ACS
failure in a loop. Fix that.
Change-Id: I97689571e147505ea2c21f271c103e3c8cc74b80
CRs-Fixed: 2215385