[vala/0.48] vala: SemanticAnalyzer.get_instance_base_type() is not allowed to return null

[Rico Tzschichholz <ricotz src gnome org>]

commit 0a812c6bde226780c74e82fd95dcc33e547af2ce
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue May 5 09:32:48 2020 +0200

    vala: SemanticAnalyzer.get_instance_base_type() is not allowed to return null
    
    This is private internal API.

 vala/valasemanticanalyzer.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/vala/valasemanticanalyzer.vala b/vala/valasemanticanalyzer.vala
index d6741f230..1404f13cd 100644
--- a/vala/valasemanticanalyzer.vala
+++ b/vala/valasemanticanalyzer.vala
@@ -849,7 +849,7 @@ public class Vala.SemanticAnalyzer : CodeVisitor {
                return true;
        }
 
-       private static DataType? get_instance_base_type (DataType instance_type, DataType base_type, 
CodeNode? node_reference) {
+       private static DataType get_instance_base_type (DataType instance_type, DataType base_type, CodeNode? 
node_reference) {
                // construct a new type reference for the base type with correctly linked type arguments
                DataType instance_base_type;
                if (base_type.type_symbol is ObjectTypeSymbol) {