warning: pointer targets differ in signedness

vp8/encoder/rdopt.c:728: warning: pointer targets in passing argument 3
of 'macro_block_yrd' differ in signedness
vp8/encoder/rdopt.c:541: note: expected 'int *' but argument is of type
'unsigned int *'

distortion is signed when calling macro_block_yrd is both other cases,
as well as for RDCOST

Change-Id: I5e22358b7da76a116f498793253aac8099cb3461
diff --git a/vp8/encoder/rdopt.c b/vp8/encoder/rdopt.c
index d1745bb..950c029 100644
--- a/vp8/encoder/rdopt.c
+++ b/vp8/encoder/rdopt.c
@@ -708,7 +708,7 @@
     MB_PREDICTION_MODE mode;
     MB_PREDICTION_MODE UNINITIALIZED_IS_SAFE(mode_selected);
     int rate, ratey;
-    unsigned int distortion;
+    int distortion;
     int best_rd = INT_MAX;
     int this_rd;
     int i;
@@ -737,7 +737,7 @@
             best_rd = this_rd;
             *Rate = rate;
             *rate_y = ratey;
-            *Distortion = (int)distortion;
+            *Distortion = distortion;
         }
     }
 
@@ -2474,4 +2474,3 @@
     return best_rd;
 }
 #endif
-