Revert "usb: gadget: f_acm: Refactor bind path to use __free()"

This reverts commit e348d18f which is
commit 47b2116e upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I1a9c6edfc49fd7b083034c7a245c88a42f415d8b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>