btrfs: replace get_seconds with new 64bit time API

The get_seconds() function is deprecated as it truncates the timestamp
to 32 bits. Change it to or ktime_get_real_seconds().

Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 9443948..4cbb1b5 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -48,7 +48,7 @@
 	int aborted;
 	struct list_head list;
 	struct extent_io_tree dirty_pages;
-	unsigned long start_time;
+	time64_t start_time;
 	wait_queue_head_t writer_wait;
 	wait_queue_head_t commit_wait;
 	wait_queue_head_t pending_wait;