Bugfix for error accumulator stats

Previous to commit de4e9e3, there was an early return in the alt-ref
case that was inadvertantly removed when the function was refactored
to return void. This patch restores the prior behavior.

Change-Id: I783ffd594a4690297e2742f99526fd7ad67698b2

vp8/encoder/pickinter.c

@@ -932,6 +932,7 @@ void vp8_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset, int re
         }
 
         x->e_mbd.mode_info_context->mbmi.mv.as_int = 0;
+        return;
     }
 
 

vp8/encoder/rdopt.c

@@ -2479,6 +2479,7 @@ void vp8_rd_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset, int
         }
 
         x->e_mbd.mode_info_context->mbmi.mv.as_int = 0;
+        return;
     }