diag: Do not update attribute of socket while closing channel

Currently while closing the socket channel we are updating
attributes of socket handle 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>