sdk: add missing "0x" prefix to unit test strings

src/sdk/src/crypto/util.rs

@@ -135,10 +135,10 @@ fn test_fp_to_u64() {
 #[test]
 fn test_fp_to_str() {
     use self::FieldElemAsStr;
-    let fpstr = "227ae0da79929f3e23f8d5bc9992f5f140f5198932378731e1b49b67fdc296c8";
+    let fpstr = "0x227ae0da79929f3e23f8d5bc9992f5f140f5198932378731e1b49b67fdc296c8";
     assert_eq!(pallas::Base::from_str(fpstr).unwrap().to_string(), fpstr);
 
-    let fpstr = "000000000000000000000000000000000000000000000000ffffffffffffffff";
+    let fpstr = "0x000000000000000000000000000000000000000000000000ffffffffffffffff";
     let fp = pallas::Base::from(u64::MAX);
     assert_eq!(fp.to_string(), fpstr);
     assert_eq!(pallas::Base::from_str(fpstr).unwrap(), fp);