[FIR] Display actual type for argument type mismatch error

Previously the argument type was being used for the actual type error
display. However, safe-call arguments are unwrapped which causes
nullable types to be displayed as non-null. Change to use the actual
type provided by the diagnostic instead of extracting the type from
the argument.

#KT-58844 Fixed

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java

@@ -22744,6 +22744,12 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/inferenceFlexibleTToNullable.kt");
             }
 
+            @Test
+            @TestMetadata("kt58844.kt")
+            public void testKt58844() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/kt58844.kt");
+            }
+
             @Test
             @TestMetadata("nullAssertOnTypeWithNullableUpperBound.kt")
             public void testNullAssertOnTypeWithNullableUpperBound() throws Exception {

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java

@@ -22744,6 +22744,12 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
                 runTest("compiler/testData/diagnostics/tests/nullableTypes/inferenceFlexibleTToNullable.kt");
             }
 
+            @Test
+            @TestMetadata("kt58844.kt")
+            public void testKt58844() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/nullableTypes/kt58844.kt");
+            }
+
             @Test
             @TestMetadata("nullAssertOnTypeWithNullableUpperBound.kt")
             public void testNullAssertOnTypeWithNullableUpperBound() throws Exception {