Revert "vsock: Fix transport_* TOCTOU"

This reverts commit 8667e8d0 which is
commit 687aa0c5 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: I86ea3bed3dc2db62fb68a08cf51bca5194509144
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>