Fix NSH PS command: If there are not argument, it would print garbage for argument list

nshlib/nsh_proccmds.c

@@ -290,7 +290,6 @@ static void ps_task(FAR struct tcb_s *tcb, FAR void *arg)
       if (ttcb->argv[1])
         {
           nsh_output(vtbl, "%p", ttcb->argv[1]);
-        }
 
           /* Then any additional arguments */
 
@@ -301,6 +300,7 @@ static void ps_task(FAR struct tcb_s *tcb, FAR void *arg)
             }
 #endif
         }
+    }
 
   nsh_output(vtbl, ")\n");
 }