VerifiedBoot: Fix incorrect mask to retrieve os_version

The os_version field in the bootimg header contains
both os_version and os_patch_level. The upper 21 bits
is the version and the lower 11 bits is os_patch_level.
An incorrect mask was used to parse the version.

Change-Id: I865bd1771a3323825525f5d985be330f4e4a1b81
1 file changed