diag: Do not update attribute of sk while closing channel

Currently while closing the socket channel we are updating
attributes of info->hdl->sk, which is already being done
by calling sock release. The patch removes the cleanup
of the same from socket channel close.

Change-Id: I05c8677c2f96c6437c4ce11153ff18577baed28e
Signed-off-by: Hardik Arya <harya@codeaurora.org>