lib: bitmap: make nbits parameter of bitmap_subset unsigned

The compiler can generate slightly smaller and simpler code when it
knows that "nbits" is non-negative.  Since no-one passes a negative
bit-count, this shouldn't affect the semantics.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/bitmap.h

@@ -109,7 +109,7 @@ extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
 extern int __bitmap_intersects(const unsigned long *bitmap1,
 			const unsigned long *bitmap2, unsigned int nbits);
 extern int __bitmap_subset(const unsigned long *bitmap1,
-			const unsigned long *bitmap2, int bits);
+			const unsigned long *bitmap2, unsigned int nbits);
 extern int __bitmap_weight(const unsigned long *bitmap, int bits);
 
 extern void bitmap_set(unsigned long *map, int i, int len);
@@ -249,7 +249,7 @@ static inline int bitmap_intersects(const unsigned long *src1,
 }
 
 static inline int bitmap_subset(const unsigned long *src1,
-			const unsigned long *src2, int nbits)
+			const unsigned long *src2, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));

lib/bitmap.c

@@ -245,9 +245,9 @@ int __bitmap_intersects(const unsigned long *bitmap1,
 EXPORT_SYMBOL(__bitmap_intersects);
 
 int __bitmap_subset(const unsigned long *bitmap1,
-				const unsigned long *bitmap2, int bits)
+		    const unsigned long *bitmap2, unsigned int bits)
 {
-	int k, lim = bits/BITS_PER_LONG;
+	unsigned int k, lim = bits/BITS_PER_LONG;
 	for (k = 0; k < lim; ++k)
 		if (bitmap1[k] & ~bitmap2[k])
 			return 0;