block, fs, mm, drivers: use bio set/get op accessors

This patch converts the simple bi_rw use cases in the block,
drivers, mm and fs code to set/get the bio operation using
bio_set_op_attrs/bio_op

These should be simple one or two liner cases, so I just did them
in one patch. The next patches handle the more complicated
cases in a module per patch.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 5b75856..c502c11 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -318,7 +318,7 @@
 		bio->bi_bdev = inode->i_sb->s_bdev;
 		bio->bi_iter.bi_sector =
 			pblk << (inode->i_sb->s_blocksize_bits - 9);
-		bio->bi_rw = WRITE;
+		bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
 		ret = bio_add_page(bio, ciphertext_page,
 					inode->i_sb->s_blocksize, 0);
 		if (ret != inode->i_sb->s_blocksize) {