diag: Rectify the name of the wcnss smd channel

Currently, APPS diag is using wrong name while opening wcnss
smd control channel. Thus wcnss control channel is not getting
opened. This patch rectifies the same.

Change-Id: I998f043403b71e2b53e9263bbdb6b05768d592b3
Signed-off-by: Katish Paran <kparan@codeaurora.org>