fuse: create fuse_do_open() helper for CUSE

Create a helper for sending an OPEN request that doesn't need a struct
inode pointer.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index ce46c12..429e669 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -528,7 +528,7 @@
 /**
  * Send OPEN or OPENDIR request
  */
-int fuse_open_common(struct inode *inode, struct file *file, int isdir);
+int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 
 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
 struct fuse_file *fuse_file_get(struct fuse_file *ff);