ACPICA: Fix possible memory leak for Scope ASL operator

Using Scope(\) to change the scope to the root could cause a
single object memory leak.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/dswload.c

@@ -639,6 +639,19 @@ acpi_ds_load2_begin_op(struct acpi_walk_state *walk_state,
 		break;
 
 	case AML_SCOPE_OP:
+
+		/* Special case for Scope(\) -> refers to the Root node */
+
+		if (op && (op->named.node == acpi_gbl_root_node)) {
+			node = op->named.node;
+
+			status =
+			    acpi_ds_scope_stack_push(node, object_type,
+						     walk_state);
+			if (ACPI_FAILURE(status)) {
+				return_ACPI_STATUS(status);
+			}
+		} else {
 			/*
 			 * The Path is an object reference to an existing object.
 			 * Don't enter the name into the namespace, but look it up
@@ -647,19 +660,22 @@ acpi_ds_load2_begin_op(struct acpi_walk_state *walk_state,
 			status =
 			    acpi_ns_lookup(walk_state->scope_info, buffer_ptr,
 					   object_type, ACPI_IMODE_EXECUTE,
-				   ACPI_NS_SEARCH_PARENT, walk_state, &(node));
+					   ACPI_NS_SEARCH_PARENT, walk_state,
+					   &(node));
 			if (ACPI_FAILURE(status)) {
 #ifdef ACPI_ASL_COMPILER
 				if (status == AE_NOT_FOUND) {
 					status = AE_OK;
 				} else {
-				ACPI_ERROR_NAMESPACE(buffer_ptr, status);
+					ACPI_ERROR_NAMESPACE(buffer_ptr,
+							     status);
 				}
 #else
 				ACPI_ERROR_NAMESPACE(buffer_ptr, status);
 #endif
 				return_ACPI_STATUS(status);
 			}
+		}
 
 		/*
 		 * We must check to make sure that the target is