app: aboot: Add check to prevent OOB Read in loading splash image

Added to check to avoid OOB Read while loading splash image and
corrected a integer overflow condition.

Change-Id: I58ce657e0607ff36c1a92c285def53527fd3a4c0
Signed-off-by: Ashish Bhimanpalliwar <abhiman@codeaurora.org>
1 file changed