usb gadget: fix a section mismatch when compiling g_ffs with CONFIG_USB_FUNCTIONFS_ETH

 commit 28824b18:
 |Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
 |Date:   Wed May 5 12:53:13 2010 +0200
 |
 |    USB: gadget: __init and __exit tags removed
 |
 |    __init, __initdata and __exit tags have have been removed from
 |    various files to make it possible for gadgets that do not use
 |    the __init/__exit tags to use those.
 obviously missed (at least) this case leading to a section mismatch in
 g_ffs.c when compiling with CONFIG_USB_FUNCTIONFS_ETH enabled.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>