DxeCore: Enforce FV/NON_FV source check

There was a bool bug in an earlier version, which unfortunately inverted
the sense of this check, but the correct (and secure) fix is to continue
to enforce the check, using the enum valuues.

Signed-off-by: Mike Beaton <mjsbeaton@gmail.com>
Signed-off-by: Marvin Häuser <mhaeuser@posteo.de>

MdeModulePkg/Core/Dxe/Image/Image.c

@@ -1235,7 +1235,7 @@ CoreLoadImageCommon (
              &ImageContext,
              FHand.Source,
              (UINT32) FHand.SourceSize,
-             UEFI_IMAGE_SOURCE_FV,
+             ImageIsFromFv ? UEFI_IMAGE_SOURCE_FV : UEFI_IMAGE_SOURCE_NON_FV,
              ImageOrigin
              );
   if (EFI_ERROR (Status)) {