src/core/lib: remove code that used undeclared functions
src/lib/hardware/vfio: function to check vfio availability
src/apps/vhost/vhost_user: check vfio before test execution
src/apps/intel/intel_app: get pci ids for test from environment variables
src/apps/vhost/vhost_user: get pci id and socket file for test from environment variables
src/core/memory: calculate size in bytes only if varialble is not null
src/Makefile: check exitcode of test
src/Makefile: ci test mode added, fails on error instead of returng 0