frudevice: debug: drop std::hex for bus

The bus is printed to debug as a decimal value everywhere in the code
except one spot.  Fix that one spot to make all debug consistent.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I04c855e377b5f2951cabd9b7505c0ad58423d63e
diff --git a/src/FruDevice.cpp b/src/FruDevice.cpp
index a7fe02b..1cd1acb 100644
--- a/src/FruDevice.cpp
+++ b/src/FruDevice.cpp
@@ -816,8 +816,8 @@
     boost::container::flat_map<std::string, std::string> formattedFru;
     if (!formatFru(device, formattedFru))
     {
-        std::cerr << "failed to format fru for device at bus " << std::hex
-                  << bus << " address " << address << "\n";
+        std::cerr << "failed to format fru for device at bus " << bus
+                  << " address " << address << "\n";
         return;
     }