devicemapper: Create helpers to cancel deferred deactivation

If a device has been scheduled for deferred deactivation and container
is started again and we need to activate device again, we need to cancel
the deferred deactivation which is already scheduled on the device.

Create a method for the same.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>

devicemapper/devmapper_log.go

@@ -22,6 +22,10 @@ func DevmapperLogCallback(level C.int, file *C.char, line C.int, dm_errno_or_cla
 		if strings.Contains(msg, "File exists") {
 			dmSawExist = true
 		}
+
+		if strings.Contains(msg, "No such device or address") {
+			dmSawEnxio = true
+		}
 	}
 
 	if dmLogger != nil {