mdss: mdp3: fix logic when verifying is image can be scaled by 1

There was an issue where images that could be scaled by 1 were not
being blit by ppp due to logic error.

Change-Id: I6f8cdf43d5398a7894e5b7f8a867ec59341345b8
Signed-off-by: Terence Hampson <thampson@codeaurora.org>