scsi: core: Remove duplicate declarations

struct request and struct request_queue are declared twice.  Remove the
duplicate declarations.

Link: https://lore.kernel.org/r/20210327030850.918018-1-wanjiabing@vivo.comSigned-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_priv.h

@@ -97,8 +97,6 @@ extern int scsi_mq_setup_tags(struct Scsi_Host *shost);
 extern void scsi_mq_destroy_tags(struct Scsi_Host *shost);
 extern void scsi_exit_queue(void);
 extern void scsi_evt_thread(struct work_struct *work);
-struct request_queue;
-struct request;
 
 /* scsi_proc.c */
 #ifdef CONFIG_SCSI_PROC_FS