qemuAgentCheckError: Use 'VIR_ERR_AGENT_COMMAND_FAILED'

In the two cases when we know that the command returned failure switch
to the new error code so that management applications can
programatically detect failure of the guest agent command.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_agent.c

@@ -985,7 +985,7 @@ qemuAgentCheckError(virJSONValue *cmd,
 
         /* Only send the user the command name + friendly error */
         if (!error) {
-            virReportError(VIR_ERR_INTERNAL_ERROR,
+            virReportError(VIR_ERR_AGENT_COMMAND_FAILED,
                            _("unable to execute QEMU agent command '%1$s'"),
                            qemuAgentCommandName(cmd));
             return -1;
@@ -999,7 +999,7 @@ qemuAgentCheckError(virJSONValue *cmd,
                 return -2;
         }
 
-        virReportError(VIR_ERR_INTERNAL_ERROR,
+        virReportError(VIR_ERR_AGENT_COMMAND_FAILED,
                        _("unable to execute QEMU agent command '%1$s': %2$s"),
                        qemuAgentCommandName(cmd),
                        qemuAgentStringifyError(error));