UnitTestFrameworkPkg: Sample unit test hangs when running in OVMF/QEMU
    
    Sample unit tests in UnitTestFrameworkPkg hangs when running in OVMF/QEMU
    environment. Build target is X64/GCC5. Fixing this issue by adding EFIAPI
    to ReportPrint() function that use VA_ARGS.
    
    Signed-off-by: Getnat Ejigu <getnatejigu@gmail.com>
    Cc: Michael D Kinney <michael.d.kinney@intel.com>
    Cc: Sean Brogan <sean.brogan@microsoft.com>
    Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
    Reviewed-by: Bret Barkelew <bret.barkelew@microsoft.com>
    Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>