patch 8.1.2402: typos and other small things

Problem:    Typos and other small things.
Solution:   Small fixes.
diff --git a/src/testdir/shared.vim b/src/testdir/shared.vim
index 78f204c..e753c1e 100644
--- a/src/testdir/shared.vim
+++ b/src/testdir/shared.vim
@@ -315,6 +315,9 @@
     let args .= ' -S Xafter.vim'
   endif
 
+  " Optionally run Vim under valgrind
+  " let cmd = 'valgrind --tool=memcheck --leak-check=yes --num-callers=25 --log-file=valgrind ' . cmd
+
   exe "silent !" . a:pipecmd . cmd . args . ' ' . a:arguments
 
   if len(a:before) > 0