Revert "splice, net: Add a splice_eof op to file-ops and socket-ops"

This reverts commit 4713b7c7 which is
commit 2bfc6685 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: I32d590ae0e683aed39bfddcd736301bce6e0dec9
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>