qemu: block: Add support for file/block/dir storage to JSON disk src generator

qemuBlockStorageSourceGetBackendProps now is able to format the JSON
definition for regular storage too.

src/qemu/qemu_block.c

@@ -577,6 +577,12 @@ qemuBlockStorageSourceGetBackendProps(virStorageSourcePtr src)
     case VIR_STORAGE_TYPE_BLOCK:
     case VIR_STORAGE_TYPE_FILE:
     case VIR_STORAGE_TYPE_DIR:
+        if (virJSONValueObjectCreate(&fileprops,
+                                     "s:driver", "file",
+                                     "s:filename", src->path, NULL) < 0)
+            return NULL;
+        break;
+
     case VIR_STORAGE_TYPE_VOLUME:
     case VIR_STORAGE_TYPE_NONE:
     case VIR_STORAGE_TYPE_LAST: