qemu: command: Use 'actualType' when deciding whether to use disk format

qemuBuildDriveSourceStr omits the disk format string when we are
emulating a 'fat' filesystem from a directory. The logic should decide
based on the 'actualType' as a disk type=pool may be converted to a
directory.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_command.c

@@ -1730,7 +1730,7 @@ qemuBuildDriveSourceStr(virDomainDiskDefPtr disk,
     }
 
     if (disk->src->format > 0 &&
-        disk->src->type != VIR_STORAGE_TYPE_DIR) {
+        actualType != VIR_STORAGE_TYPE_DIR) {
         const char *qemuformat = virStorageFileFormatTypeToString(disk->src->format);
         if (rawluks)
             qemuformat = "luks";