help: fix a typo in the list of warning categories

* lib/Automake/ChannelDefs.pm (usage): s/none'/none/.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/lib/Automake/ChannelDefs.pm b/lib/Automake/ChannelDefs.pm
index 524b8f5bb631b7485911604716cbe75ed0fea73d..02ce8493f7f370e7947a5f4716ef794274deff36 100644 (file)
--- a/lib/Automake/ChannelDefs.pm
+++ b/lib/Automake/ChannelDefs.pm
@@ -194,7 +194,7 @@ Warning categories include:
   unsupported        unsupported or incomplete features (default)
   all                all the warnings
   no-CATEGORY        turn off warnings in CATEGORY
-  none'              turn off all the warnings
+  none               turn off all the warnings
   error              treat warnings as errors
 EOF
 }