[rygel] lms: Fix potential null access warnings

[Jens Georg <jensgeorg src gnome org>]

commit 129fd36a3f2a9060a7c56ebdfe4d189a358f95bf
Author: Jens Georg <mail jensge org>
Date:   Thu Feb 13 23:54:43 2020 +0100

    lms: Fix potential null access warnings

 src/plugins/lms/rygel-lms-category-container.vala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/plugins/lms/rygel-lms-category-container.vala 
b/src/plugins/lms/rygel-lms-category-container.vala
index 4ff3cce0..46456db2 100644
--- a/src/plugins/lms/rygel-lms-category-container.vala
+++ b/src/plugins/lms/rygel-lms-category-container.vala
@@ -188,10 +188,10 @@ public abstract class Rygel.LMS.CategoryContainer : Rygel.MediaContainer,
 
         if (expression is LogicalExpression) {
             return CategoryContainer.logical_expression_to_sql
-                                        (expression as LogicalExpression, args);
+                                        ((LogicalExpression) expression, args);
         } else {
             return CategoryContainer.relational_expression_to_sql
-                                        (expression as RelationalExpression,
+                                        ((RelationalExpression) expression,
                                          args);
         }
     }
@@ -320,7 +320,7 @@ public abstract class Rygel.LMS.CategoryContainer : Rygel.MediaContainer,
                     object = child;
                 } else {
                     /* try grandchildren */
-                    var container = child as CategoryContainer;
+                    var container = (CategoryContainer) child;
                     object = yield container.find_object (id, cancellable);
 
                     /* tell object to keep a reference to the parent --