Revert "RDMA/core: Don't expose hw_counters outside of init net namespace"

This reverts commit 0cf80f92 which is
commit a1ecb30f 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: I807645cd6cf8b5ff178eee8bdb7286c3662d0d83
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>