[hebao2] fix complition warning (#2373)

Author: dong77

packages/hebao_v2/contracts/base/libwallet/GuardianLib.sol

@@ -388,11 +388,11 @@ library GuardianLib
         )
         private
         view
-        returns (Guardian memory)
+        returns (Guardian memory guardian)
     {
         uint pos = wallet.guardianIdx[addr];
         if (pos > 0) {
-            return wallet.guardians[pos - 1];
+            guardian = wallet.guardians[pos - 1];
         }
     }
 

packages/hebao_v2/contracts/thirdparty/strings.sol

@@ -44,9 +44,9 @@ library strings {
         uint _ptr;
     }
 
-    function memcpy(uint dest, uint src, uint len) private pure {
+    function memcpy(uint dest, uint src, uint _len) private pure {
         // Copy word-length chunks while possible
-        for(; len >= 32; len -= 32) {
+        for(; _len >= 32; _len -= 32) {
             assembly {
                 mstore(dest, mload(src))
             }
@@ -55,7 +55,7 @@ library strings {
         }
 
         // Copy remaining bytes
-        uint mask = 256 ** (32 - len) - 1;
+        uint mask = 256 ** (32 - _len) - 1;
         assembly {
             let srcpart := and(mload(src), not(mask))
             let destpart := and(mload(dest), mask)