Fix krealloc() alignment

bcachefs assumes kmalloc & krealloc give out allocations that are
naturally aligned, like the kernel allocators do.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

include/linux/slab.h

@@ -40,7 +40,7 @@ static inline void *krealloc(void *old, size_t size, gfp_t flags)
 
 	run_shrinkers();
 
-	new = malloc(size);
+	new = kmalloc(size, flags);
 	if (!new)
 		return NULL;