alpha: fix __arch_hweight32 typo

Typo in 1527bc8b renamed hweight32 to
__arch_weight32.
Signed-off-by: NMatt Turner <mattst88@gmail.com>

arch/alpha/include/asm/bitops.h

@@ -410,7 +410,7 @@ static inline unsigned long __arch_hweight64(unsigned long w)
 	return __kernel_ctpop(w);
 }
 
-static inline unsigned int __arch_weight32(unsigned int w)
+static inline unsigned int __arch_hweight32(unsigned int w)
 {
 	return __arch_hweight64(w);
 }