Staging: usbip: fix typos concerning "sequential"

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

drivers/staging/usbip/usbip_common.h

@@ -172,7 +172,7 @@ struct usbip_header_basic {
 #define USBIP_RET_UNLINK	0x0004
 	__u32 command;
 
-	 /* sequencial number which identifies requests.
+	 /* sequential number which identifies requests.
 	  * incremented per connections */
 	__u32 seqnum;