bcachefs: Make bucket_alloc tracepoint more readable

Print bucket in dev:bucket notation, to be consistent with how we refer
to buckets elsewhere.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/trace.h

@@ -530,7 +530,7 @@ DECLARE_EVENT_CLASS(bucket_alloc,
 		s, nonblocking, err),
 
 	TP_STRUCT__entry(
-		__field(dev_t,			dev			)
+		__field(u8,			dev			)
 		__array(char,	reserve,	16			)
 		__field(bool,			user	)
 		__field(u64,			bucket	)
@@ -548,7 +548,7 @@ DECLARE_EVENT_CLASS(bucket_alloc,
 	),
 
 	TP_fast_assign(
-		__entry->dev		= ca->dev;
+		__entry->dev		= ca->dev_idx;
 		strscpy(__entry->reserve, alloc_reserve, sizeof(__entry->reserve));
 		__entry->user		= user;
 		__entry->bucket		= bucket;
@@ -565,10 +565,10 @@ DECLARE_EVENT_CLASS(bucket_alloc,
 		strscpy(__entry->err, err, sizeof(__entry->err));
 	),
 
-	TP_printk("%d,%d reserve %s user %u bucket %llu free %llu avail %llu copygc_wait %llu/%lli seen %llu open %llu need_journal_commit %llu nouse %llu nocow %llu nonblocking %u err %s",
-		  MAJOR(__entry->dev), MINOR(__entry->dev),
+	TP_printk("reserve %s user %u bucket %u:%llu free %llu avail %llu copygc_wait %llu/%lli seen %llu open %llu need_journal_commit %llu nouse %llu nocow %llu nonblocking %u err %s",
 		  __entry->reserve,
 		  __entry->user,
+		  __entry->dev,
 		  __entry->bucket,
 		  __entry->free,
 		  __entry->avail,