iwlwifi: mvm: fix comparison of u32 variable with less than zero

The comparison of the u32 variable wgds_tbl_idx with less than zero is
always going to be false because it is unsigned.  Fix this by making
wgds_tbl_idx a plain signed int.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 4fd445a2 ("iwlwifi: mvm: Add log information about SAR status")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/nvm.c

@@ -620,7 +620,7 @@ void iwl_mvm_rx_chub_update_mcc(struct iwl_mvm *mvm,
 	enum iwl_mcc_source src;
 	char mcc[3];
 	struct ieee80211_regdomain *regd;
-	u32 wgds_tbl_idx;
+	int wgds_tbl_idx;
 
 	lockdep_assert_held(&mvm->mutex);