Use the correct help output for the ps command

It should not look like this:

```
meterpreter > ps -h
Usage: ps [ options ]

OPTIONS:
 -S       Search string to filter by
 -h 		This help menu
```

It should not not look like this:

```
meterpreter > ps -h
Use the command with no arguments to see all running processes.
The following options can be used to filter those results:

OPTIONS:

    -A <opt>  Filters processes on architecture (x86 or x86_64)
    -S <opt>  String to search for (converts to regex)
    -U <opt>  Filters processes on the user using the supplied RegEx
    -h        Help menu.
    -s        Show only SYSTEM processes
```

Author: Brent Cook

lib/rex/post/meterpreter/ui/console/command_dispatcher/stdapi/sys.rb

@@ -436,12 +436,7 @@ def cmd_ps(*args)
             return true
           end
         when '-h'
-          print_line "Usage: ps [ options ]"
-          print_line
-          print_line "OPTIONS:"
-          print_line " -S       Search string to filter by"
-          print_line " -h 		This help menu"
-          print_line
+          cmd_ps_help
           return 0
       when "-A"
         print_line "Filtering on arch..."
@@ -491,7 +486,6 @@ def cmd_ps(*args)
       'SearchTerm' => search_term)
 
     processes.each { |ent|
-
       session = ent['session'] == 0xFFFFFFFF ? '' : ent['session'].to_s
       arch    = ent['arch']
 
@@ -503,8 +497,6 @@ def cmd_ps(*args)
       row = [ ent['pid'].to_s, ent['name'], arch, session, ent['user'], ent['path'] ]
 
       tbl << row #if (search_term.nil? or row.join(' ').to_s.match(search_term))
-
-
     }
 
     if (processes.length == 0)