mm/frontswap: fix uninit'ed variable warning

Fixes uninitialized variable warning on 'type' in frontswap_shrink().
type is set before use by __frontswap_unuse_pages() called by
__frontswap_shrink() called by frontswap_shrink() before use by
try_to_unuse().

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

mm/frontswap.c

@@ -292,7 +292,7 @@ static int __frontswap_shrink(unsigned long target_pages,
 void frontswap_shrink(unsigned long target_pages)
 {
 	unsigned long pages_to_unuse = 0;
-	int type, ret;
+	int uninitialized_var(type), ret;
 
 	/*
 	 * we don't want to hold swap_lock while doing a very