mm: Export symbol ksize()

Commit 7b2cd92adc ("crypto: api - Fix
zeroing on free") added modular user of ksize(). Export that to fix
crypto.ko compilation.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

mm/slub.c

@@ -2736,6 +2736,7 @@ size_t ksize(const void *object)
 	 */
 	return s->size;
 }
+EXPORT_SYMBOL(ksize);
 
 void kfree(const void *x)
 {