msm: msm_bus: Clean up the bus scaling driver

Floor vote data needs to be protected with mutex
lock to avoid double free of memory due to race condtion.
Also fix the compilation errors.

Change-Id: I53a5b6faefed346f200c9a99905e9098f65705bb
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>