dm: use DMDEBUG macros now that they use pr_debug variants

Now that DMDEBUG uses pr_debug and DMDEBUG_LIMIT uses
pr_debug_ratelimited cleanup DM's 2 direct pr_debug callers to use
them to get the benefit of consistent DM_FMT formatting of debugging
messages.

While doing so, dm-mpath.c:dm_report_EIO() was switched over to using
DMDEBUG_LIMIT due to the potential for error handling floods in the IO
completion path.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 74246d7..95f16d8 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -439,7 +439,7 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
 }
 
 /*
- * dm_report_EIO() is a macro instead of a function to make pr_debug()
+ * dm_report_EIO() is a macro instead of a function to make pr_debug_ratelimited()
  * report the function name and line number of the function from which
  * it has been invoked.
  */
@@ -447,11 +447,11 @@ static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
 do {									\
 	struct mapped_device *md = dm_table_get_md((m)->ti->table);	\
 									\
-	pr_debug("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d\n", \
-		 dm_device_name(md),					\
-		 test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags),	\
-		 test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags),	\
-		 dm_noflush_suspending((m)->ti));			\
+	DMDEBUG_LIMIT("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d", \
+		      dm_device_name(md),				\
+		      test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags),	\
+		      test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags), \
+		      dm_noflush_suspending((m)->ti));			\
 } while (0)
 
 /*