Revert "tcp: convert elligible sysctls to u8"

This reverts commit cc9f9a49 which is
commit 4ecc1baf upstream.

It breaks the Android kernel abi, and is not needed at this point in
time.  If it is required, it can come back in an ABI-safe way.

Bug: 161946584
Change-Id: Ia44a4d7ef5887b2175038783e918badf464ae51b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>