Revert "tracefs: Use generic inode RCU for synchronizing freeing"

This reverts commit 726f4c24 which is
commit 0b6743bd 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: I516217b9fff7a72d0bddc8c5570b8e4e0f89966f
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>