Propagate GetContainer error from event processor

Before this change we just accept that any error is "not found" and it
could be something else, but even if it it is just a "not found" kind of
error this should be dealt with from the container store and not the
event processor.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit 54e30a6)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/monitor.go

@@ -2,8 +2,6 @@ package daemon // import "github.com/docker/docker/daemon"
 
 import (
 	"context"
-	"errors"
-	"fmt"
 	"runtime"
 	"strconv"
 	"time"
@@ -12,6 +10,7 @@ import (
 	"github.com/docker/docker/container"
 	libcontainerdtypes "github.com/docker/docker/libcontainerd/types"
 	"github.com/docker/docker/restartmanager"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
@@ -29,8 +28,8 @@ func (daemon *Daemon) setStateCounter(c *container.Container) {
 // ProcessEvent is called by libcontainerd whenever an event occurs
 func (daemon *Daemon) ProcessEvent(id string, e libcontainerdtypes.EventType, ei libcontainerdtypes.EventInfo) error {
 	c, err := daemon.GetContainer(id)
-	if c == nil || err != nil {
-		return fmt.Errorf("no such container: %s", id)
+	if err != nil {
+		return errors.Wrapf(err, "could not find container %s", id)
 	}
 
 	switch e {