[PATCH] mempolicy.c compile fix, make sure BITS_PER_BYTE is defined

Gar..

mm/mempolicy.c: In function 'get_nodes':
mm/mempolicy.c:527: error: 'BITS_PER_BYTE' undeclared (first use in this function)
mm/mempolicy.c:527: error: (Each undeclared identifier is reported only once
mm/mempolicy.c:527: error: for each function it appears in.)

About to retry a build with the below patch which should do the trick.
(How did this *ever* build?)
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

include/linux/types.h

@@ -8,6 +8,7 @@
 	(((bits)+BITS_PER_LONG-1)/BITS_PER_LONG)
 #define DECLARE_BITMAP(name,bits) \
 	unsigned long name[BITS_TO_LONGS(bits)]
+#define BITS_PER_BYTE 8
 #endif
 
 #include <linux/posix_types.h>