r8152: reduce the number of Tx

Because the Tx has the features of stopping queue and aggregation,
We don't need many tx buffers. Change the tx number from 10 to 4
to reduce the usage of the memory. This could save 16K * 6 bytes
memory.

Signed-off-by: Hayes Wang <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/usb/r8152.c

···
 	FULL_DUP	= 0x01,
 };
 
-#define RTL8152_MAX_TX		10
+#define RTL8152_MAX_TX		4
 #define RTL8152_MAX_RX		10
 #define INTBUFSIZE		2
 #define CRC_SIZE		4