FIR2IR: don't generate default parameters for delegated members

#KT-55465 Fixed

compiler/testData/ir/irText/firProblems/ErrorInDefaultValue.fir.ir.txt

@@ -58,8 +58,6 @@ FILE fqName:<root> fileName:/ErrorInDefaultValue.kt
         public abstract fun f (x: kotlin.String): kotlin.String declared in <root>.A
       $this: VALUE_PARAMETER name:<this> type:<root>.C
       VALUE_PARAMETER name:x index:0 type:kotlin.String
-        EXPRESSION_BODY
-          ERROR_EXPR 'Stub expression for default value of x' type=kotlin.String
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public open fun f (x: kotlin.String): kotlin.String declared in <root>.C'
           CALL 'public abstract fun f (x: kotlin.String): kotlin.String declared in <root>.A' type=kotlin.String origin=null