fix(inputs.temp): ignore warnings returned by gopsutil

The temperature sensor reading can return warnings as an error.
Previously we ignored these, but they were removed from gopsutil. The
warning was returned to gopsutil and we should continue to ignore
warnings and only fail on a true error.

fixes: influxdata#12841

plugins/inputs/system/ps.go

@@ -215,7 +215,14 @@ func (s *SystemPS) SwapStat() (*mem.SwapMemoryStat, error) {
 }
 
 func (s *SystemPS) Temperature() ([]host.TemperatureStat, error) {
-	return host.SensorsTemperatures()
+	temp, err := host.SensorsTemperatures()
+	if err != nil {
+		_, ok := err.(*host.Warnings)
+		if !ok {
+			return temp, err
+		}
+	}
+	return temp, nil
 }
 
 func (s *SystemPSDisk) Partitions(all bool) ([]disk.PartitionStat, error) {