msm: mdss: Correction in cyclical reading of histogram bins

The iteration condition in loop for reading histogram bin has an
error. We are essentially missing out on the value of one bin.

Change-Id: I713ad6c580374173b38cd1a1f4f8120f55cf1452
Signed-off-by: Krishna Chaitanya Parimi <cparimi@codeaurora.org>