ts-depriv-audit-qemu: Increase depriv-fd-checker timeout

ts-depriv-audit-qemu: Increase depriv-fd-checker timeout

This check currently fails on "sabro*" machines, when running on
"qemu-mainline" branch. It takes about 35 seconds when running
manually while the default timeout is only 30s.

Increase timeout so that the machine as more time to run this bundle
of perl, binary and python (fishdescriptor called by
osstest-depriv-fd-collector, and probably the culprit for longer run
time).

Signed-off-by: Anthony PERARD <anthony@xenproject.org>