patch 8.2.3096: temp files remain after running tests

Problem:    Temp files remain after running tests.
Solution:   Delete the right files. (Dominique Pellé, closes #8509)
diff --git a/src/testdir/test_debugger.vim b/src/testdir/test_debugger.vim
index bb3a246..97e115b 100644
--- a/src/testdir/test_debugger.vim
+++ b/src/testdir/test_debugger.vim
@@ -975,8 +975,7 @@
   call RunDbgCmd(buf, 'cont')
 
   call StopVimInTerminal(buf)
-  call delete('Xtest1.vim')
-  call delete('Xtest2.vim')
+  call delete('XtestDebug.vim')
 endfunc
 
 func Test_debug_def_function()