Address http://bugzilla.kernel.org/show_bug.cgi?id=7189

It should check `clen', not `len'.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <jurij@wooyd.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: <stable@kernel.org>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>