patch 8.2.3786: test fails because of using Vim9 syntax in legacy function

Problem:    Test fails because of using Vim9 syntax in legacy function.
Solution:   Add "call".
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 1fe56f3..64e0bbc 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2239,7 +2239,7 @@
       let Time = 'localtime'
       call Time()
   END
-  CheckScriptFailure(lines, 'E1085:')
+  call CheckScriptFailure(lines, 'E1085:')
 endfunc
 
 func Test_char2nr()