iwlwifi: make some functions friendly to sparse

Somehow, sparse cannot track the cond_lock() here properly,
but if we return directly from the inner basic block then
it doesn't complain. Refactor the code a bit to make it not
complain.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20220130115024.3f9de2d59929.Ib6324e93951ee877754538c89f3ab2a84998bd40@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/iwl-io.c

@@ -65,14 +65,14 @@ IWL_EXPORT_SYMBOL(iwl_poll_bit);
 
 u32 iwl_read_direct32(struct iwl_trans *trans, u32 reg)
 {
-	u32 value = 0x5a5a5a5a;
-
 	if (iwl_trans_grab_nic_access(trans)) {
-		value = iwl_read32(trans, reg);
+		u32 value = iwl_read32(trans, reg);
+
 		iwl_trans_release_nic_access(trans);
+		return value;
 	}
 
-	return value;
+	return 0x5a5a5a5a;
 }
 IWL_EXPORT_SYMBOL(iwl_read_direct32);
 
@@ -135,13 +135,15 @@ IWL_EXPORT_SYMBOL(iwl_write_prph64_no_grab);
 
 u32 iwl_read_prph(struct iwl_trans *trans, u32 ofs)
 {
-	u32 val = 0x5a5a5a5a;
-
 	if (iwl_trans_grab_nic_access(trans)) {
-		val = iwl_read_prph_no_grab(trans, ofs);
+		u32 val = iwl_read_prph_no_grab(trans, ofs);
+
 		iwl_trans_release_nic_access(trans);
+
+		return val;
 	}
-	return val;
+
+	return 0x5a5a5a5a;
 }
 IWL_EXPORT_SYMBOL(iwl_read_prph);