cryptonote_protocol: simplify and remove unnecessary casts

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -291,13 +291,14 @@ namespace cryptonote
     /* As I don't know if accessing hshd from core could be a good practice,
     I prefer pushing target height to the core at the same time it is pushed to the user.
     Nz. */
-    m_core.set_target_blockchain_height(static_cast<int64_t>(hshd.current_height));
+    m_core.set_target_blockchain_height((hshd.current_height));
     int64_t diff = static_cast<int64_t>(hshd.current_height) - static_cast<int64_t>(m_core.get_current_blockchain_height());
-	int64_t max_block_height = max(static_cast<int64_t>(hshd.current_height),static_cast<int64_t>(m_core.get_current_blockchain_height()));
-	int64_t last_block_v1 = m_core.get_testnet() ? 624633 : 1009826;
-	int64_t diff_v2 = max_block_height > last_block_v1 ? min(abs(diff), max_block_height - last_block_v1) : 0;
+    uint64_t abs_diff = std::abs(diff);
+    uint64_t max_block_height = max(hshd.current_height,m_core.get_current_blockchain_height());
+    uint64_t last_block_v1 = m_core.get_testnet() ? 624633 : 1009826;
+    uint64_t diff_v2 = max_block_height > last_block_v1 ? min(abs_diff, max_block_height - last_block_v1) : 0;
     MCLOG(is_inital ? el::Level::Info : el::Level::Debug, "global", context <<  "Sync data returned a new top block candidate: " << m_core.get_current_blockchain_height() << " -> " << hshd.current_height
-      << " [Your node is " << std::abs(diff) << " blocks (" << ((abs(diff) - diff_v2) / (24 * 60 * 60 / DIFFICULTY_TARGET_V1)) + (diff_v2 / (24 * 60 * 60 / DIFFICULTY_TARGET_V2)) << " days) "
+      << " [Your node is " << abs_diff << " blocks (" << ((abs_diff - diff_v2) / (24 * 60 * 60 / DIFFICULTY_TARGET_V1)) + (diff_v2 / (24 * 60 * 60 / DIFFICULTY_TARGET_V2)) << " days) "
       << (0 <= diff ? std::string("behind") : std::string("ahead"))
       << "] " << ENDL << "SYNCHRONIZATION started");
     }