cli/parser: Only prefix short options with one dash

- This avoids error messages like:

```
➜ brew list -l
Error: Invalid usage: `--l` cannot be passed without `--formula`.
```

Library/Homebrew/cli/parser.rb

@@ -533,8 +533,8 @@ module Homebrew
 
     class OptionConstraintError < UsageError
       def initialize(arg1, arg2, missing: false)
-        arg1 = "--#{arg1.tr("_", "-")}"
-        arg2 = "--#{arg2.tr("_", "-")}"
+        arg1 = arg1.length > 1 ? "--#{arg1.tr("_", "-")}" : "-#{arg1.tr("_", "-")}"
+        arg2 = arg2.length > 1 ? "--#{arg2.tr("_", "-")}" : "-#{arg2.tr("_", "-")}"
 
         message = if missing
           "`#{arg2}` cannot be passed without `#{arg1}`."