ringct: do not require range proof in decodeRct/decodeRctSimple

These fields aren't used, and they'll actually be pruned in
some cases

src/ringct/rctSigs.cpp

@@ -873,8 +873,7 @@ namespace rct {
     //   must know the destination private key to find the correct amount, else will return a random number    
     xmr_amount decodeRct(const rctSig & rv, const key & sk, unsigned int i, key & mask) {
         CHECK_AND_ASSERT_MES(rv.type == RCTTypeFull, false, "decodeRct called on non-full rctSig");
-        CHECK_AND_ASSERT_THROW_MES(rv.p.rangeSigs.size() > 0, "Empty rv.p.rangeSigs");
-        CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.p.rangeSigs.size(), "Mismatched sizes of rv.outPk and rv.p.rangeSigs");
+        CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.ecdhInfo.size(), "Mismatched sizes of rv.outPk and rv.ecdhInfo");
         CHECK_AND_ASSERT_THROW_MES(i < rv.ecdhInfo.size(), "Bad index");
 
         //mask amount and mask
@@ -902,8 +901,7 @@ namespace rct {
 
     xmr_amount decodeRctSimple(const rctSig & rv, const key & sk, unsigned int i, key &mask) {
         CHECK_AND_ASSERT_MES(rv.type == RCTTypeSimple, false, "decodeRct called on non simple rctSig");
-        CHECK_AND_ASSERT_THROW_MES(rv.p.rangeSigs.size() > 0, "Empty rv.p.rangeSigs");
-        CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.p.rangeSigs.size(), "Mismatched sizes of rv.outPk and rv.p.rangeSigs");
+        CHECK_AND_ASSERT_THROW_MES(rv.outPk.size() == rv.ecdhInfo.size(), "Mismatched sizes of rv.outPk and rv.ecdhInfo");
         CHECK_AND_ASSERT_THROW_MES(i < rv.ecdhInfo.size(), "Bad index");
 
         //mask amount and mask