changed ProccessorId type to *string, cause wmi sometimes returns nil for it

cpu/cpu_windows.go

@@ -19,7 +19,7 @@ type Win32_Processor struct {
 	Manufacturer              string
 	Name                      string
 	NumberOfLogicalProcessors uint32
-	ProcessorId               string
+	ProcessorId               *string
 	Stepping                  *string
 	MaxClockSpeed             uint32
 }
@@ -62,6 +62,9 @@ func CPUInfo() ([]CPUInfoStat, error) {
 	if err != nil {
 		return ret, err
 	}
+	
+	procID := ""
+	
 	for i, l := range dst {		
 		cpu := CPUInfoStat{
 			CPU:        int32(i),
@@ -69,7 +72,7 @@ func CPUInfo() ([]CPUInfoStat, error) {
 			VendorID:   l.Manufacturer,
 			ModelName:  l.Name,
 			Cores:      int32(l.NumberOfLogicalProcessors),
-			PhysicalID: l.ProcessorId,
+			PhysicalID: procID,
 			Mhz:        float64(l.MaxClockSpeed),
 			Flags:      []string{},
 		}