patch 8.2.0424: checking for wrong return value

Problem:    Checking for wrong return value. (Tom)
Solution:   Invert the check and fix the test.

src/testdir/test_vim9_script.vim

@@ -943,13 +943,20 @@ def Test_while_loop()
 enddef
 
 def Test_interrupt_loop()
+  let caught = false
   let x = 0
+  try
     while 1
       x += 1
       if x == 100
         feedkeys("\<C-C>", 'Lt')
       endif
     endwhile
+  catch
+    caught = true
+    assert_equal(100, x)
+  endtry
+  assert_true(caught, 'should have caught an exception')
 enddef
 
 def Test_substitute_cmd()

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    424,
 /**/
     423,
 /**/

src/vim9execute.c

@@ -487,7 +487,7 @@ call_def_function(
 	{
 	    // Turn CTRL-C into an exception.
 	    got_int = FALSE;
-	    if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) != FAIL)
+	    if (throw_exception("Vim:Interrupt", ET_INTERRUPT, NULL) == FAIL)
 		goto failed;
 	    did_throw = TRUE;
 	}