pvmfw: DRY vcpufreq error path & prevent panic am: 8ba89801e0 am: b40dd6c7f3

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/2963846

Change-Id: If984c592072ed6c5de8df94cb0b13e7a74f43f25
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>