udf: Fix compilation warnings when UDF debug is on

Fix two compilation warnings (and actual bugs in message formatting)
when UDF debugging is turned on.

Signed-off-by: Sebastian Manciulea <manciuleas@yahoo.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h
index 30f664a..61897d3 100644
--- a/fs/udf/udfdecl.h
+++ b/fs/udf/udfdecl.h
@@ -16,7 +16,7 @@
 #define UDF_PREALLOCATE
 #define UDF_DEFAULT_PREALLOC_BLOCKS	8
 
-#undef UDFFS_DEBUG
+#define UDFFS_DEBUG
 
 #ifdef UDFFS_DEBUG
 #define udf_debug(f, a...) \