usb: gadget: f_hid: fix refcount leak on error path

usb: gadget: f_hid: fix refcount leak on error path

When failing to allocate report_desc, opts->refcnt has already been
incremented so it needs to be decremented to avoid leaving the options
structure permanently locked.

Fixes: 21a9476a7ba8 ("usb: gadget: hid: add configfs support")
Tested-by: Lee Jones <lee@kernel.org>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Lee Jones <lee@kernel.org>
Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221122123523.3068034-3-john@metanate.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>