[PATCH 2/7] vfs: Introduce the fd closing helper

[George Spelvin]

About this patch, one thing to note: the comment about checking for a
NULL filp should go with do_close() (where the resultant goto out_unlock
is located) rather than sys_close.

While we're doing minor cleanups, you might add:

 SYSCALL_DEFINE1(close, unsigned int, fd)
 {
-	int retval;
-
-	retval = do_close(fd);
+	int retval = do_close(fd);