Revert "net: fix information leakage in /proc/net/ptype"

This reverts commit e372ecd4 which is
commit 47934e06b65637c88a762d9c98329ae6e3238888 upstream.

It causes an abi break, and is not anything that the Android kernels
worry about, so revert it.

Fixes: e372ecd4 ("net: fix information leakage in /proc/net/ptype")
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I76aa3718185ce6bc3e1941f68b7f574fda49d08a