Revert "usb: gadget: inode.c: fix unbalanced spin_lock in ep0_write"

This reverts commit abb540b5 which is
commit b7bd98b7db9f upstream.  I had added it to make another patch
apply cleanly, but as Ben points out, that was wrong.

Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: David Eccher <d.eccher@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>