cachefiles: Explicitly cast enumerated type in put_object

Clang warns when one enumerated type is implicitly converted to another.

fs/cachefiles/namei.c:247:50: warning: implicit conversion from
enumeration type 'enum cachefiles_obj_ref_trace' to different
enumeration type 'enum fscache_obj_ref_trace' [-Wenum-conversion]
        cache->cache.ops->put_object(&xobject->fscache,
cachefiles_obj_put_wait_retry);

Silence this warning by explicitly casting to fscache_obj_ref_trace,
which is also done in put_object.
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

fs/cachefiles/namei.c

@@ -244,11 +244,13 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
 
 	ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags));
 
-	cache->cache.ops->put_object(&xobject->fscache, cachefiles_obj_put_wait_retry);
+	cache->cache.ops->put_object(&xobject->fscache,
+		(enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry);
 	goto try_again;
 
 requeue:
-	cache->cache.ops->put_object(&xobject->fscache, cachefiles_obj_put_wait_timeo);
+	cache->cache.ops->put_object(&xobject->fscache,
+		(enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo);
 	_leave(" = -ETIMEDOUT");
 	return -ETIMEDOUT;
 }