cnss2: Assert if unexpected second QMI server arrive comes

Only one QMI server arrive should come for WLFW service. Hence only
assert if unexpected second server arrive comes for debug purpose.

Change-Id: Ib8cf80a544038904685a3d3a054fc7f3189a4a30
Signed-off-by: Yue Ma <yuem@codeaurora.org>