fix: reset change state after power operation

According to
https://github.com/vmware/open-vm-tools/blob/stable-12.4.5/open-vm-tools/services/plugins/powerOps/powerOps.c#L225,
after power operations we need to reset the state to
GUESTOS_STATECHANGE_NONE.

Signed-off-by: Robin Elfrink <[email protected]>

internal/tboxcmds/power.go

@@ -10,7 +10,7 @@ import (
 
 // vmware/guestrpc/powerops.h.
 const (
-	_ = iota
+	PowerStateNone = iota
 	PowerStateHalt
 	PowerStateReboot
 	PowerStatePowerOn
@@ -52,6 +52,12 @@ func (op powerOp) HandleCommand([]byte) ([]byte, error) {
 
 	rc := nanotoolbox.RpciOK
 
+	// Let the host know we're considering the state change
+	msg := fmt.Sprintf("tools.os.statechange.status %s%d\x00", rc, op.state)
+	if _, err := op.out.Request([]byte(msg)); err != nil {
+		return nil, fmt.Errorf("error sending %q: %w", msg, err)
+	}
+
 	if op.handler != nil {
 		if err := op.handler(); err != nil {
 			l.WithError(err).Error("error handling power operation")
@@ -60,7 +66,8 @@ func (op powerOp) HandleCommand([]byte) ([]byte, error) {
 		}
 	}
 
-	msg := fmt.Sprintf("tools.os.statechange.status %s%d\x00", rc, op.state)
+	// Send the result and reset the state change
+	msg = fmt.Sprintf("tools.os.statechange.status %s%d\x00", rc, PowerStateNone)
 	if _, err := op.out.Request([]byte(msg)); err != nil {
 		return nil, fmt.Errorf("error sending %q: %w", msg, err)
 	}