patch 8.2.1183: assert_fails() checks the last error message

Problem:    assert_fails() checks the last error message.
Solution:   Check the first error, it is more relevant.  Fix all the tests
            that rely on the old behavior.
diff --git a/src/testdir/test_normal.vim b/src/testdir/test_normal.vim
index a4dc619..68aae53 100644
--- a/src/testdir/test_normal.vim
+++ b/src/testdir/test_normal.vim
@@ -1384,7 +1384,7 @@
   call setline(1, '---')
   call assert_fails('normal! ggv2lK', 'E349:')
   call setline(1, ['abc', 'xyz'])
-  call assert_fails("normal! gg2lv2h\<C-]>", 'E426:')
+  call assert_fails("normal! gg2lv2h\<C-]>", 'E433:')
   call assert_beeps("normal! ggVjK")
 
   " clean up