bcache: Refactor request_write()

Try to improve some of the naming a bit to be more consistent, and also
improve the flow of control in request_write() a bit.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/btree.h b/drivers/md/bcache/btree.h
index 967aacd..ea0814b 100644
--- a/drivers/md/bcache/btree.h
+++ b/drivers/md/bcache/btree.h
@@ -260,7 +260,7 @@
 	} type:8;
 
 	unsigned		csum:1;
-	unsigned		skip:1;
+	unsigned		bypass:1;
 	unsigned		flush_journal:1;
 
 	unsigned		insert_data_done:1;