brew-info: Add pinned status to info.

Closes Homebrew/homebrew#18851.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/cmd/info.rb

@@ -79,7 +79,7 @@ module Homebrew extend self
     specs << "devel #{f.devel.version}" if f.devel
     specs << "HEAD" if f.head
 
-    puts "#{f.name}: #{specs*', '}"
+    puts "#{f.name}: #{specs*', '}#{' (pinned)' if f.pinned?}"
 
     puts f.homepage