usb_blaster: ublast_access.h: add guard macro

Change-Id: I10f6e2048cf88f64f5dce275a273783365afd65c
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Reviewed-on: http://openocd.zylin.com/1941
Tested-by: jenkins
Reviewed-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

src/jtag/drivers/usb_blaster/ublast_access.h

@@ -22,6 +22,9 @@
  *
  */
 
+#ifndef JTAG_UBLAST_ACCESS_H
+#define JTAG_UBLAST_ACCESS_H
+
 #include <libusb_common.h>
 
 /* Low level flags */
@@ -64,3 +67,5 @@ struct ublast_lowlevel {
 extern struct ublast_lowlevel *ublast_register_ftdi(void);
 extern struct ublast_lowlevel *ublast_register_ftd2xx(void);
 extern struct ublast_lowlevel *ublast2_register_libusb(void);
+
+#endif /* JTAG_UBLAST_ACCESS_H */