usb/gadget: fix kernel-doc warning

Fix kernel-doc warning, wrong parameter name listed:

Warning(lin2627-g3-kdocfixes//drivers/usb/gadget/config.c:183): No description found for parameter 'match'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>