staging: greybus: arpc.h: remove duplicate line.

Fix checkpatch.pl issue of the form:
"CHECK: Please don't use multiple blank lines".
Signed-off-by: Nathan Howard <adanhawthorn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/arpc.h

@@ -74,7 +74,6 @@ struct arpc_response_message {
 	__u8	result;		/* Result of RPC */
 } __packed;
 
-
 /* ARPC requests */
 #define ARPC_TYPE_CPORT_CONNECTED		0x01
 #define ARPC_TYPE_CPORT_QUIESCE			0x02