[PATCH] Broken CLEAR_BITMAP() macro

The CLEAR_BITMAP() macro in include/linux/types.h is broken and doesn't
round the bitmap size to the proper 'long' boundary.

This fixes it by creating a macro BITS_TO_LONGS that just rounds a
number of bits up to the closest number of unsigned longs.  This makes
the DECLARE & CLEAR _BITMAP macros more readable and fixes the bug.

include/linux/types.h

@@ -4,10 +4,12 @@
 #ifdef	__KERNEL__
 #include <linux/config.h>
 
+#define BITS_TO_LONGS(bits) \
+	(((bits)+BITS_PER_LONG-1)/BITS_PER_LONG)
 #define DECLARE_BITMAP(name,bits) \
-	unsigned long name[((bits)+BITS_PER_LONG-1)/BITS_PER_LONG]
+	unsigned long name[BITS_TO_LONGS(bits)]
 #define CLEAR_BITMAP(name,bits) \
-	memset(name, 0, ((bits)+BITS_PER_LONG-1)/8)
+	memset(name, 0, BITS_TO_LONGS(bits)*sizeof(unsigned long))
 #endif
 
 #include <linux/posix_types.h>