iwlwifi: use upper_32_bits/lower_32_bits where appropriate

That's a bit nicer than open-coding it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-io.c b/drivers/net/wireless/intel/iwlwifi/iwl-io.c
index a9f69fd..0f893ae 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-io.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-io.c
@@ -54,8 +54,8 @@ IWL_EXPORT_SYMBOL(iwl_write32);
 void iwl_write64(struct iwl_trans *trans, u64 ofs, u64 val)
 {
 	trace_iwlwifi_dev_iowrite64(trans->dev, ofs, val);
-	iwl_trans_write32(trans, ofs, val & 0xffffffff);
-	iwl_trans_write32(trans, ofs + 4, val >> 32);
+	iwl_trans_write32(trans, ofs, lower_32_bits(val));
+	iwl_trans_write32(trans, ofs + 4, upper_32_bits(val));
 }
 IWL_EXPORT_SYMBOL(iwl_write64);