Export virDomainRedirdevDefFree

In the 162efa1a commit the function was introduced, but the
commit forgot to update livirt_private.syms accordingly.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/libvirt_private.syms

@@ -424,6 +424,7 @@ virDomainPMSuspendedReasonTypeFromString;
 virDomainPMSuspendedReasonTypeToString;
 virDomainRedirdevBusTypeFromString;
 virDomainRedirdevBusTypeToString;
+virDomainRedirdevDefFree;
 virDomainRNGBackendTypeToString;
 virDomainRNGDefFree;
 virDomainRNGFind;