unittest flaky: pkg/storage/fs/posix/tree/tree_test.go

[rhafer]

The unit test for the watchfs feature seem to be flaky. It's not always the same test that are failig. Here are a few occasion:

• https://ci.opencloud.rocks/repos/4/pipeline/241/157
• https://ci.opencloud.rocks/repos/4/pipeline/229/157
• https://ci.opencloud.rocks/repos/4/pipeline/197/160

[rhafer]

https://ci.opencloud.rocks/repos/4/pipeline/241/157 logs: opencloud-eu-reva-241-test.log

https://ci.opencloud.rocks/repos/4/pipeline/229/157 logs: opencloud-eu-reva-229-test.log

https://ci.opencloud.rocks/repos/4/pipeline/197/160 logs: opencloud-eu-reva-197-test.log