[media] em28xx: fix two severe bugs in function em2800_i2c_recv_bytes()

Function em2800_i2c_recv_bytes() has 2 severe bugs:
1) It does not wait for the i2c read to complete before reading the received message content from the bridge registers.
2) Reading more than 1 byte doesn't work
The former can result in data corruption, the latter always does.
The rewritten code also superseds the content of function
em2800_i2c_check_for_device().
Tested with device "Terratec Cinergy 200 USB".

[mchehab@redhat.com: Fix CodingStyle issues]
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index f891a28..2aa4b84 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -194,7 +194,7 @@
 */
 
 /* time in msecs to wait for i2c writes to finish */
-#define EM2800_I2C_WRITE_TIMEOUT 20
+#define EM2800_I2C_XFER_TIMEOUT		20
 
 enum em28xx_mode {
 	EM28XX_SUSPEND,