maple_tree: use correct variable type in sizeof

The type of variable pointed to by pivs is unsigned long, but the type
used in sizeof is a pointer type.  Change it to unsigned long.

This change has no runtime effect, as sizeof(ul) == sizeof(ul *).

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 54a611b ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <[email protected]>
Reported-by: David Binderman <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

lib/maple_tree.c

@@ -3258,7 +3258,7 @@ static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end
 
 		if (tmp < max_p)
 			memset(pivs + tmp, 0,
-			       sizeof(unsigned long *) * (max_p - tmp));
+			       sizeof(unsigned long) * (max_p - tmp));
 
 		if (tmp < mt_slots[mt])
 			memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp));