iwlagn: usersapce application decide the size of trace buffer

For testmode trace function, allow userspace application to request the
size of trace buffer.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index c8de236..a7d2159 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -1170,6 +1170,8 @@
 
 #ifdef CONFIG_IWLWIFI_DEVICE_SVTOOL
 struct iwl_testmode_trace {
+	u32 buff_size;
+	u32 total_size;
 	u8 *cpu_addr;
 	u8 *trace_addr;
 	dma_addr_t dma_addr;