tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK

Fix building failures when CONFIG_BLOCK == n.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A2F1520.8020003@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/blktrace_api.h

@@ -218,7 +218,7 @@ static inline int blk_trace_init_sysfs(struct device *dev)
 
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 
-#ifdef CONFIG_EVENT_TRACING
+#if defined(CONFIG_EVENT_TRACING) && defined(CONFIG_BLOCK)
 
 static inline int blk_cmd_buf_len(struct request *rq)
 {
@@ -229,7 +229,7 @@ extern void blk_dump_cmd(char *buf, struct request *rq);
 extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
 extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq);
 
-#endif /* CONFIG_EVENT_TRACING */
+#endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
 
 #endif /* __KERNEL__ */
 #endif