includecheck fix: include/drm, drm_memory.h

fix the following 'make includecheck' warning:

  include/drm/drm_memory.h: linux/vmalloc.h is included more than once.
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
LKML-Reference: <1247068169.4382.99.camel@ht.satnam>
Acked-by: NDave Airlie <airlied@redhat.com>

include/drm/drm_memory.h

@@ -44,8 +44,6 @@
 
 #if __OS_HAS_AGP
 
-#include <linux/vmalloc.h>
-
 #ifdef HAVE_PAGE_AGP
 #include <asm/agp.h>
 #else