diag: dci: Safeguard to prevent integer overflow
At certain point in diag driver there can be integer overflow thus can lead to memory leak. Added a safegaurd for it. Change-Id: I9347405d8f1f95ed42fe0abf35cbf4c362281bdf CRs-fixed: 565160 Signed-off-by: Katish Paran <kparan@codeaurora.org>

Signed-off-by: evolutionmod <kernelcraft@gmail.com>