Remove extraneous check in DependencyResolver.

At this point in the method we already know that aspect != null,
because we're in the else-branch of an if (aspect == null).

--
MOS_MIGRATED_REVID=104674784
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java b/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java
index d0aff0f7..63e9012 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/DependencyResolver.java
@@ -260,9 +260,7 @@
     } else {
       attributes = new ArrayList<>();
       attributes.addAll(rule.getRuleClassObject().getAttributes());
-      if (aspect != null) {
-        attributes.addAll(aspect.getAttributes().values());
-      }
+      attributes.addAll(aspect.getAttributes().values());
     }
 
     ImmutableSortedKeyListMultimap.Builder<Attribute, LabelAndConfiguration> result =