qcacld-3.0: Change argument data type from int to unsigned int

kstrtouint() expects 3rd argument to be of data type unsigned int,
but currently argument of type int is passed.
Fix this by changing int to unsigned int.

Change-Id: I8263de9a4a9260da91dac6be021c54a927390a9a
CRs-Fixed: 2423711

core/hdd/src/wlan_hdd_ioctl.c

@@ -5726,7 +5726,7 @@ static int drv_cmd_set_mc_rate(struct hdd_adapter *adapter,
 {
 	int ret = 0;
 	uint8_t *value = command;
-	int target_rate = 0;
+	uint32_t target_rate = 0;
 
 	/* input value is in units of hundred kbps */