patch 9.0.0611: tests delete files with a separate delete() call

Problem:    Tests delete files with a separate delete() call.
Solution:   Use deferred delete.
diff --git a/src/testdir/test_find_complete.vim b/src/testdir/test_find_complete.vim
index 920d765..079fb78 100644
--- a/src/testdir/test_find_complete.vim
+++ b/src/testdir/test_find_complete.vim
@@ -10,7 +10,7 @@
   call delete("Xfind", "rf")
   let cwd = getcwd()
   let test_out = cwd . '/test.out'
-  call mkdir('Xfind')
+  call mkdir('Xfind', 'R')
   cd Xfind
 
   new
@@ -158,7 +158,6 @@
 
   enew | only
   call chdir(cwd)
-  call delete('Xfind', 'rf')
   set path&
 endfunc