block: fix for block tracing build error

block/compat_ioctl.c: In function 'compat_blkdev_ioctl':
block/compat_ioctl.c:754: error: 'BLKTRACESETUP32' undeclared (first use in this function)

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

include/linux/blktrace_api.h

@@ -204,17 +204,6 @@ extern int blk_trace_init_sysfs(struct device *dev);
 
 extern struct attribute_group blk_trace_attr_group;
 
-struct compat_blk_user_trace_setup {
-	char name[32];
-	u16 act_mask;
-	u32 buf_size;
-	u32 buf_nr;
-	compat_u64 start_lba;
-	compat_u64 end_lba;
-	u32 pid;
-};
-#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
-
 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 # define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
 # define blk_trace_shutdown(q)				do { } while (0)
@@ -232,6 +221,21 @@ static inline int blk_trace_init_sysfs(struct device *dev)
 
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 
+#ifdef CONFIG_COMPAT
+
+struct compat_blk_user_trace_setup {
+	char name[32];
+	u16 act_mask;
+	u32 buf_size;
+	u32 buf_nr;
+	compat_u64 start_lba;
+	compat_u64 end_lba;
+	u32 pid;
+};
+#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
+
+#endif
+
 #if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
 
 static inline int blk_cmd_buf_len(struct request *rq)