Completion: when Unit is expected do not prioritize by return type

Decide on completion order by other factors
Previously would prefer callable that return Unit if Unit is the expected type
    leading to strange completion order

 #KT-25588 Fixed

idea/ide-common/src/org/jetbrains/kotlin/idea/util/FuzzyType.kt

@@ -135,6 +135,7 @@ class FuzzyType(
     private fun matchedSubstitutor(otherType: FuzzyType, matchKind: MatchKind): TypeSubstitutor? {
         if (type.isError) return null
         if (otherType.type.isError) return null
+        if (otherType.type.isUnit() && matchKind == MatchKind.IS_SUBTYPE) return TypeSubstitutor.EMPTY
 
         fun KotlinType.checkInheritance(otherType: KotlinType): Boolean {
             return when (matchKind) {