package/xvisor: fix build with gcc 10

Fixes:
 - http://autobuild.buildroot.org/results/b6070c0721b33824e71833ce53423979980aa598

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
1 file changed