Fixing comparison types.

Trusty treats comparison of signed and unsigned types as an error during
build. This fixes the instances where that was being done in
system/keymaster.

Bug: 190665713
Test: Trusty RKP builds
Change-Id: Ib4fb75357e16d142824f292e3c31207f77805807
Merged-In: Ib4fb75357e16d142824f292e3c31207f77805807
2 files changed