frame_superres: Set superres scale to 1:1 at init

The superres scale was not initialized correctly, which prevented
regular resizing if CONFIG_FRAME_SUPERRES was set. This patch
initializes superres scaling to 1:1 so it won't interfere with anything
else.

Change-Id: I9e3c89e91a4eb66146b9b924e8c19d0ed44a8dc4

av1/encoder/encoder.c

@@ -2743,6 +2743,9 @@ AV1_COMP *av1_create_compressor(AV1EncoderConfig *oxcf,
 #endif
 
   av1_loop_filter_init(cm);
+#if CONFIG_FRAME_SUPERRES
+  cm->superres_scale_numerator = SUPERRES_SCALE_DENOMINATOR;
+#endif  // CONFIG_FRAME_SUPERRES
 #if CONFIG_LOOP_RESTORATION
   av1_loop_restoration_precal();
 #endif  // CONFIG_LOOP_RESTORATION