package/eudev: fix build with older gcc

package/eudev: fix build with older gcc

Initialisers for anonymous unions/structs are unknown to gcc-4.5, still
widely used.

Fixes:
    http://autobuild.buildroot.org/results/11e/11ebb926b891862e270b9cb39fd2ed4344b736a8/
    http://autobuild.buildroot.org/results/065/065fdef50b1dd57b95ad2b5eda9904a1d0787cdc/
    http://autobuild.buildroot.org/results/316/3161eb96da66936e2cb3ec6aa5547587c3d90338/
    http://autobuild.buildroot.org/results/226/2267a204e9eb46bcb621f5bd408deaca98709fc3/

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>