stream: remove redundant checks

src/input/stream.c

@@ -1857,10 +1857,7 @@ static int AStreamReadDir( stream_t *s, input_item_node_t *p_node )
 {
     access_t *p_access = s->p_sys->p_access;
 
-    if( p_access->pf_readdir != NULL )
-        return p_access->pf_readdir( p_access, p_node );
-    else
-        return VLC_ENOITEM;
+    return p_access->pf_readdir( p_access, p_node );
 }
 
 /**

src/input/stream_filter.c

@@ -130,8 +130,6 @@ static void StreamDelete( stream_t *s )
 
 int stream_FilterDefaultReadDir( stream_t *s, input_item_node_t *p_node )
 {
-    if( s != NULL && s->p_source != NULL )
-        return stream_ReadDir( s->p_source, p_node );
-    else
-        return VLC_ENOITEM;
+    assert( s->p_source != NULL );
+    return stream_ReadDir( s->p_source, p_node );
 }