Use correct function to check for function type in InlineParameterChecker

There's no use of noinline/crossinline modifiers on parameters of _subtypes_ of
function types

 #KT-11411 Fixed

compiler/testData/diagnostics/tests/modifiers/inlineParameters.kt

@@ -9,3 +9,12 @@ fun gav(<!ILLEGAL_INLINE_PARAMETER_MODIFIER!>noinline<!> x: (Int) -> Unit, <!ILL
 inline fun correct(noinline x: (Int) -> Unit, crossinline y: (String) -> Int) {}
 
 <!NOTHING_TO_INLINE!>inline<!> fun incompatible(<!INCOMPATIBLE_MODIFIERS!>noinline<!> <!INCOMPATIBLE_MODIFIERS!>crossinline<!> x: () -> String) {}
+
+class FunctionSubtype : () -> Unit {
+    override fun invoke() {}
+}
+
+<!NOTHING_TO_INLINE!>inline<!> fun functionSubtype(
+        <!ILLEGAL_INLINE_PARAMETER_MODIFIER!>noinline<!> f: FunctionSubtype,
+        <!ILLEGAL_INLINE_PARAMETER_MODIFIER!>crossinline<!> g: FunctionSubtype
+) { }