bus: check if D-Bus service name request was successful

Solves issue #21 on github.

Change-Id: I71ef2be8b2a2fc8ff82410b6aed12c76140b5606
Signed-off-by: Waqar Hameed <waqarh@axis.com>
diff --git a/sdbusplus/bus.hpp.in b/sdbusplus/bus.hpp.in
index e01d1f2..e80d5ed 100644
--- a/sdbusplus/bus.hpp.in
+++ b/sdbusplus/bus.hpp.in
@@ -186,7 +186,11 @@
      */
     void request_name(const char* service)
     {
-        _intf->sd_bus_request_name(_bus.get(), service, 0);
+        int r = _intf->sd_bus_request_name(_bus.get(), service, 0);
+        if (r < 0)
+        {
+            throw exception::SdBusError(-r, "sd_bus_request_name");
+        }
     }
 
     /** @brief Create a method_call message.