iwlwifi: remove iwl_check_bits

The function is used exactly once, and the caller
doesn't even need the special check, it can be
simplified to a simple bit check.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

diff --cc drivers/net/wireless/iwlwifi/iwl-3945.c
Simple merge

diff --cc drivers/net/wireless/iwlwifi/iwl-helpers.h
Simple merge