treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

net/decnet/Kconfig

@@ -4,7 +4,7 @@
 #
 config DECNET
 	tristate "DECnet Support"
-	---help---
+	help
 	  The DECnet networking protocol was used in many products made by
 	  Digital (now Compaq).  It provides reliable stream and sequenced
 	  packet communications over which run a variety of services similar
@@ -29,7 +29,7 @@ config DECNET_ROUTER
 	bool "DECnet: router support"
 	depends on DECNET
 	select FIB_RULES
-	---help---
+	help
 	  Add support for turning your DECnet Endnode into a level 1 or 2
 	  router.  This is an experimental, but functional option.  If you
 	  do say Y here, then make sure that you also say Y to "Kernel/User