Revert "platform: Provide a remove callback that returns no value"

This reverts commit d18789f4 which is
commit 5c5a7680 upstream.

It breaks the Android ABI and is not really needed for this branch at
all, so it can be safely reverted.

Bug: 161946584
Change-Id: I0546f81b6ad24145f4f984676064850728282cc3
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>