xen/blkback: Remove the unused typedefs.

	uint8_t         operation;       /* copied from request */

	int16_t         status;          /* BLKIF_RSP_???       */

};

typedef struct blkif_x86_32_request blkif_x86_32_request_t;

typedef struct blkif_x86_32_response blkif_x86_32_response_t;

#pragma pack(pop)

/* x86_64 protocol version */

	uint8_t         operation;       /* copied from request */

	int16_t         status;          /* BLKIF_RSP_???       */

};

typedef struct blkif_x86_64_request blkif_x86_64_request_t;

typedef struct blkif_x86_64_response blkif_x86_64_response_t;

DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,

		  struct blkif_common_response);