vc1pred: remove logically dead code

CC: libav-stable@libav.org
Bug-Id: CID 1245699 / CID 1245700

libavcodec/vc1_pred.c

@@ -648,7 +648,7 @@ void ff_vc1_pred_mv_intfr(VC1Context *v, int n, int dmv_x, int dmv_y,
                 } else if (c_valid) {
                     px = C[0];
                     py = C[1];
-                } else px = py = 0;
+                }
             } else {
                 if (field_a && a_valid) {
                     px = A[0];
@@ -656,11 +656,7 @@ void ff_vc1_pred_mv_intfr(VC1Context *v, int n, int dmv_x, int dmv_y,
                 } else if (field_b && b_valid) {
                     px = B[0];
                     py = B[1];
-                } else if (c_valid) {
-                    px = C[0];
-                    py = C[1];
-                } else
-                    px = py = 0;
+                }
             }
         } else if (total_valid == 1) {
             px = (a_valid) ? A[0] : ((b_valid) ? B[0] : C[0]);