Redundant 'suspend' modifier inspection: don't report when function has suspend operator invoke

#KT-25465 Fixed

idea/src/org/jetbrains/kotlin/idea/highlighter/KotlinSuspendCallLineMarkerProvider.kt

@@ -79,6 +79,7 @@ private fun KtExpression.isValidCandidateExpression(): Boolean {
     if (this is KtOperationReferenceExpression || this is KtForExpression || this is KtProperty || this is KtNameReferenceExpression) return true
     val parent = parent
     if (parent is KtCallExpression && parent.calleeExpression == this) return true
+    if (this is KtCallExpression && this.calleeExpression is KtCallExpression) return true
     return false
 }
 

idea/testData/inspections/redundantSuspendModifier/operators.kt

@@ -37,6 +37,11 @@ class C(val x: Int, val y: Int) {
     suspend operator fun invoke() = x + y
 }
 
+// Not redundant
+suspend fun bar(): Int {
+    return C(1, 2)()
+}
+
 // Not redundant
 suspend fun foo(c1: C, c2: C): Int {
     return c1() + c2()