fuse: split out readdir.c

Directory reading code is about to grow larger, so split it out from dir.c
into a new source file.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile
index 60da84a..f7b807b 100644
--- a/fs/fuse/Makefile
+++ b/fs/fuse/Makefile
@@ -5,4 +5,4 @@
 obj-$(CONFIG_FUSE_FS) += fuse.o
 obj-$(CONFIG_CUSE) += cuse.o
 
-fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o
+fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o