mm: Export symbol ksize()

Commit 7b2cd92adc5430b0c1adeb120971852b4ea1ab08 ("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>
diff --git a/mm/slob.c b/mm/slob.c
index bf7e8fc..52bc8a2 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -521,6 +521,7 @@
 	} else
 		return sp->page.private;
 }
+EXPORT_SYMBOL(ksize);
 
 struct kmem_cache {
 	unsigned int size, align;