Valgrind complained:

==3770== Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s)
==3770==    at 0x919D407: ioctl (syscall-template.S:81)
==3770==    by 0x530FE7E: rpl_ioctl (ioctl.c:42)
==3770==    by 0x50CB433: virNetDevFeatureAvailable (virnetdev.c:2764)
==3770==    by 0x50CB6A7: virNetDevGetFeatures (virnetdev.c:2830)
==3770==    by 0x1F0E5347: udevProcessNetworkInterface (node_device_udev.c:722)
==3770==    by 0x1F0E689F: udevGetDeviceDetails (node_device_udev.c:1300)
==3770==    by 0x1F0E6E06: udevAddOneDevice (node_device_udev.c:1422)
==3770==    by 0x1F0E6FB8: udevProcessDeviceListEntry (node_device_udev.c:1464)
==3770==    by 0x1F0E70CF: udevEnumerateDevices (node_device_udev.c:1494)
==3770==    by 0x1F0E7BB4: nodeStateInitialize (node_device_udev.c:1806)
==3770==    by 0x51B4303: virStateInitialize (libvirt.c:777)
==3770==    by 0x11DEE7: daemonRunStateInit (libvirtd.c:906)
==3770==  Address 0x228e38d4 is on thread 12's stack
==3770==  in frame #2, created by virNetDevFeatureAvailable (virnetdev.c:2750)

* src/util/virnetdev.c (virNetDevFeatureAvailable): Initialize all
bytes of ifr.
Signed-off-by: NEric Blake <eblake@redhat.com>