usb: gadget: udc: renesas_usb3: should remove debugfs

usb: gadget: udc: renesas_usb3: should remove debugfs

BugLink: http://bugs.launchpad.net/bugs/1790188
commit 1990cf7c21ea185cec98c6d45a82c04481261e35 upstream.

This patch fixes an issue that this driver doesn't remove its debugfs.

Fixes: 43ba968b00ea ("usb: gadget: udc: renesas_usb3: add debugfs to set the b-device mode")
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>