pipe: add pipe_buf_get() helper

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 0a6a808..b50220c 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1963,7 +1963,7 @@
 			pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
 			pipe->nrbufs--;
 		} else {
-			ibuf->ops->get(pipe, ibuf);
+			pipe_buf_get(pipe, ibuf);
 			*obuf = *ibuf;
 			obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
 			obuf->len = rem;