msm: ipa: rmnet_ipa: Fix to decrement the client upon disconenct

After lan client disconenct client counter is not decremented.
Due to which, the stats of lan client is not reset and leads
to incorrect stats upon next connect.
Fix to decrement the counter upon disconnect.

Looks like this is a propagation miss due to code
merge conflicts from previous kernel version.

Change-Id: I3506c65dd66e550724c51cd79f40556a15366af4
Signed-off-by: Mohammed <mjavid@codeaurora.org>