[media] DiB0700: get rid of on-stack dma buffers

This patch removes the on-stack buffers for USB DMA transfers.

This is an alternative version of the patch discussed by Florian here:
http://thread.gmane.org/gmane.linux.kernel/1115695/Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <patrick.boettcher@dibcom.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-usb/dib0700.h

@@ -46,8 +46,9 @@ struct dib0700_state {
 	u8 is_dib7000pc;
 	u8 fw_use_new_i2c_api;
 	u8 disable_streaming_master_mode;
-    u32 fw_version;
-    u32 nb_packet_buffer_size;
+	u32 fw_version;
+	u32 nb_packet_buffer_size;
+	u8 buf[255];
 };
 
 extern int dib0700_get_version(struct dvb_usb_device *d, u32 *hwversion,