Do not report UNNECESSARY_SAFE_CALL on ErrorType

compiler/testData/diagnostics/tests/SafeCallUnknownType.fir.kt

@@ -0,0 +1,7 @@
+// !WITH_NEW_INFERENCE
+import com.unknown
+
+fun ff() {
+    val a = <!UNRESOLVED_REFERENCE!>unknown<!>()
+    val b = a?.plus(42)
+}

compiler/testData/diagnostics/tests/SafeCallUnknownType.kt

@@ -0,0 +1,7 @@
+// !WITH_NEW_INFERENCE
+import <!UNRESOLVED_REFERENCE!>com<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>unknown<!>
+
+fun ff() {
+    val a = <!UNRESOLVED_REFERENCE!>unknown<!>()
+    val <!UNUSED_VARIABLE!>b<!> = <!TYPE_MISMATCH{OI}!><!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a<!>?.<!DEBUG_INFO_MISSING_UNRESOLVED!>plus<!>(42)<!>
+}

compiler/testData/diagnostics/tests/SafeCallUnknownType.txt

@@ -0,0 +1,3 @@
+package
+
+public fun ff(): kotlin.Unit