linting: assigned to src, but reassigned without using the value (was…

…tedassign)

    cli/command/container/opts.go:928:2: assigned to src, but reassigned without using the value (wastedassign)
        src := ""
        ^

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 3dfdaa6)
Signed-off-by: Cory Snider <csnider@mirantis.com>

cli/command/container/opts.go

@@ -911,8 +911,7 @@ func parseDevice(device, serverOS string) (container.DeviceMapping, error) {
 // parseLinuxDevice parses a device mapping string to a container.DeviceMapping struct
 // knowing that the target is a Linux daemon
 func parseLinuxDevice(device string) (container.DeviceMapping, error) {
-	src := ""
-	dst := ""
+	var src, dst string
 	permissions := "rwm"
 	arr := strings.Split(device, ":")
 	switch len(arr) {