Use named error return for initProcess#start

Signed-off-by: Ted Yu <[email protected]>

libcontainer/process_linux.go

@@ -279,7 +279,7 @@ func (p *initProcess) waitForChildExit(childPid int) error {
 	return nil
 }
 
-func (p *initProcess) start() error {
+func (p *initProcess) start() (retErr error) {
 	defer p.messageSockPair.parent.Close()
 	err := p.cmd.Start()
 	p.process.ops = p
@@ -302,7 +302,7 @@ func (p *initProcess) start() error {
 		}
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			// TODO: should not be the responsibility to call here
 			p.manager.Destroy()
 			if p.intelRdtManager != nil {
@@ -349,15 +349,6 @@ func (p *initProcess) start() error {
 		return newSystemErrorWithCause(err, "waiting for our first child to exit")
 	}
 
-	defer func() {
-		if err != nil {
-			// TODO: should not be the responsibility to call here
-			p.manager.Destroy()
-			if p.intelRdtManager != nil {
-				p.intelRdtManager.Destroy()
-			}
-		}
-	}()
 	if err := p.createNetworkInterfaces(); err != nil {
 		return newSystemErrorWithCause(err, "creating network interfaces")
 	}