cnss2: Avoid excessive runtime PM put operation

When runtime PM is active, the usage count should never become
negative. Hence avoid excessive runtime PM put operation. However,
it just tries to remedy from occasional bad state so the root issue
still need to be checked if this kind of situation happens.

Change-Id: I39021a98c25008d7bf4062e5fdd09bc7359f34d2
Signed-off-by: Yue Ma <yuem@codeaurora.org>