iwlwifi: mvm: fix the type we use in the PPAG table validity checks

The value we receive from ACPI is a long long unsigned integer but the
values should be treated as signed char.  When comparing the received
value with ACPI_PPAG_MIN_LB/HB, we were doing an unsigned comparison,
so the negative value would actually be treated as a very high number.

To solve this issue, assign the value to our table of s8's before
making the comparison, so the value is already converted when we do
so.
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210210135352.b0ec69f312bc.If77fd9c61a96aa7ef2ac96d935b7efd7df502399@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

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

@@ -965,16 +965,23 @@ static int iwl_mvm_get_ppag_table(struct iwl_mvm *mvm)
 			union acpi_object *ent;
 
 			ent = &wifi_pkg->package.elements[idx++];
-			if (ent->type != ACPI_TYPE_INTEGER ||
-			    (j == 0 && ent->integer.value > ACPI_PPAG_MAX_LB) ||
-			    (j == 0 && ent->integer.value < ACPI_PPAG_MIN_LB) ||
-			    (j != 0 && ent->integer.value > ACPI_PPAG_MAX_HB) ||
-			    (j != 0 && ent->integer.value < ACPI_PPAG_MIN_HB)) {
-				ppag_table.v1.enabled = cpu_to_le32(0);
+			if (ent->type != ACPI_TYPE_INTEGER) {
 				ret = -EINVAL;
 				goto out_free;
 			}
+
 			gain[i * num_sub_bands + j] = ent->integer.value;
+
+			if ((j == 0 &&
+			     (gain[i * num_sub_bands + j] > ACPI_PPAG_MAX_LB ||
+			      gain[i * num_sub_bands + j] < ACPI_PPAG_MIN_LB)) ||
+			    (j != 0 &&
+			     (gain[i * num_sub_bands + j] > ACPI_PPAG_MAX_HB ||
+			      gain[i * num_sub_bands + j] < ACPI_PPAG_MIN_HB))) {
+				ppag_table.v1.enabled = cpu_to_le32(0);
+				ret = -EINVAL;
+				goto out_free;
+			}
 		}
 	}
 	ret = 0;