Changed the parameter 'char * data' of process_start to the

type process_data_t. This was an artifact when the choice was
made to use the void * type for the data parameter in processes.

Changed parameter 'void * data' of process_post_synch to
process_data_t for consistency.

Checked all the uses of process_start() in contiki and fixed casts
of the data parameter.

apps/shell/shell-rime-netcmd.c

@@ -159,7 +159,7 @@ recv_trickle(struct trickle_conn *c)
     
     if(crc == crc16_data(msg->netcmd, len, 0)) {
       /* Start the server process with the incoming command. */
-      process_start(&shell_netcmd_server_process, msg->netcmd);
+      process_start(&shell_netcmd_server_process, (void *)msg->netcmd);
     }
   }
 }