For consistency with the LMAC functions, rename the UMAC scan stop
function to iwl_mvm_umac_scan_stop().  Additionally, move things
around a bit to avoid an unnecessary forward declaration.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>