patch 9.1.0464: no whitespace padding in commentstring option in ftplugins

Problem:  no whitespace padding in commentstring option in ftplugins
Solution: Change default to include whitespace padding, update
          existing filetype plugins with the new default value
          (Riley Bruins)

closes: #14843

Signed-off-by: Riley Bruins <ribru17@hotmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/c.vim b/runtime/ftplugin/c.vim
index e2eebc5..378d580 100644
--- a/runtime/ftplugin/c.vim
+++ b/runtime/ftplugin/c.vim
@@ -2,6 +2,7 @@
 " Language:	C
 " Maintainer:	The Vim Project <https://github.com/vim/vim>
 " Last Change:	2023 Aug 22
+"		2024 Jun 02 by Riley Bruins <ribru17@gmail.com> ('commentstring')
 " Former Maintainer:	Bram Moolenaar <Bram@vim.org>
 
 " Only do this when not done yet for this buffer
@@ -24,7 +25,7 @@
 
 " These options have the right value as default, but the user may have
 " overruled that.
-setlocal commentstring& define& include&
+setlocal commentstring=/*\ %s\ */ define& include&
 
 " Set completion with CTRL-X CTRL-O to autoloaded function.
 if exists('&ofu')