[PATCH] typo in vmscan.c

From: Christoph Lameter <clameter@sgi.com>

Looks like a comma was left from the conversion from a struct to an
assignment.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>