udf: use get_bh()

Make UDF use get_bh() instead of directly accessing b_count and use
brelse() instead of udf_release_data() which does just brelse()...

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/udf/partition.c b/fs/udf/partition.c
index dabf2b8..467a261 100644
--- a/fs/udf/partition.c
+++ b/fs/udf/partition.c
@@ -81,7 +81,7 @@
 
 	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
 
-	udf_release_data(bh);
+	brelse(bh);
 
 	if (UDF_I_LOCATION(UDF_SB_VAT(sb)).partitionReferenceNum == partition)
 	{