dm: use dynamic debug instead of compile-time config option

Switch to use dynamic debug to avoid having recompile the kernel
just to enable debugging messages.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

include/linux/device-mapper.h

@@ -559,13 +559,8 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
 #define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
 
-#ifdef CONFIG_DM_DEBUG
-#define DMDEBUG(fmt, ...) printk(KERN_DEBUG DM_FMT(fmt), ##__VA_ARGS__)
+#define DMDEBUG(fmt, ...) pr_debug(DM_FMT(fmt), ##__VA_ARGS__)
 #define DMDEBUG_LIMIT(fmt, ...) pr_debug_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
-#else
-#define DMDEBUG(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
-#define DMDEBUG_LIMIT(fmt, ...) no_printk(fmt, ##__VA_ARGS__)
-#endif
 
 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
 			  0 : scnprintf(result + sz, maxlen - sz, x))