patch 8.2.4892: test failures because of changed error messages

Problem:    Test failures because of changed error messages.
Solution:   Adjust the exptected error messages.
diff --git a/src/testdir/test_tcl.vim b/src/testdir/test_tcl.vim
index a4554bb..bfd7013 100644
--- a/src/testdir/test_tcl.vim
+++ b/src/testdir/test_tcl.vim
@@ -711,7 +711,7 @@
   call assert_fails('tcl exit x', 'expected integer but got "x"')
 
   tcl set foo "foo"
-  call assert_fails('tcl exit 3', 'E572: exit code 3')
+  call assert_fails('tcl exit 3', 'E572: Exit code 3')
 
   " The Tcl interpreter should have been deleted and a new one
   " is re-created with the next :tcl command.