RedundantLetInspection: remove 'let' safe call correctly

#KT-37148 Fixed

idea/src/org/jetbrains/kotlin/idea/inspections/RedundantLetInspection.kt

@@ -146,7 +146,7 @@ private fun KtDotQualifiedExpression.applyTo(element: KtCallExpression) {
 }
 
 private fun deleteCall(element: KtCallExpression) {
-    val parent = element.parent as? KtDotQualifiedExpression
+    val parent = element.parent as? KtQualifiedExpression
     if (parent != null) {
         val replacement = parent.selectorExpression?.takeIf { it != element } ?: parent.receiverExpression
         parent.replace(replacement)

idea/testData/inspectionsLocal/simpleRedundantLet/reference5.kt

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+val a = 1?.let<caret> { it }?.let { it }

idea/testData/inspectionsLocal/simpleRedundantLet/reference5.kt.after

@@ -0,0 +1,2 @@
+// WITH_RUNTIME
+val a = 1?.let { it }

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -12450,6 +12450,11 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/simpleRedundantLet/reference4.kt");
         }
 
+        @TestMetadata("reference5.kt")
+        public void testReference5() throws Exception {
+            runTest("idea/testData/inspectionsLocal/simpleRedundantLet/reference5.kt");
+        }
+
         @TestMetadata("sameLets.kt")
         public void testSameLets() throws Exception {
             runTest("idea/testData/inspectionsLocal/simpleRedundantLet/sameLets.kt");