Remove dummy PRIszX macros for formatting

Size specifiers are no longer needed now that we use typesafe tinyformat
for string formatting, instead of the system's sprintf.

No functional changes.

This continues the work in #3735.

src/wallet.cpp

@@ -1638,7 +1638,7 @@ bool CWallet::TopUpKeyPool(unsigned int kpSize)
             if (!walletdb.WritePool(nEnd, CKeyPool(GenerateNewKey())))
                 throw runtime_error("TopUpKeyPool() : writing generated key failed");
             setKeyPool.insert(nEnd);
-            LogPrintf("keypool added key %d, size=%"PRIszu"\n", nEnd, setKeyPool.size());
+            LogPrintf("keypool added key %d, size=%u\n", nEnd, setKeyPool.size());
         }
     }
     return true;