Remove redundant if from UnmappedTargetPropertiesInspection (#115)

Author: hduelme

src/main/java/org/mapstruct/intellij/inspection/UnmappedTargetPropertiesInspection.java

@@ -174,11 +174,7 @@ private static PsiType getTargetType(PsiMethod method) {
                 || !( isMapper( containingClass ) || isMapperConfig( containingClass ) ) ) {
                 return null;
             }
-            PsiType targetType = TargetUtils.getRelevantType( method );
-            if ( targetType == null ) {
-                return null;
-            }
-            return targetType;
+            return TargetUtils.getRelevantType( method );
         }
     }