fuse_t_session: Correctly handle EOF

[griff]

The fuse-t session uses a socket pair for communication but wasn't correctly handling EOF and so when trying to gracefully unmount it would just hang. This change simply deals with EOF in the channel and returns None when it occurs during header read and an error otherwise.

[bergwolf]

lgtm, but please cargo fmt your code, thanks!

[griff]

lgtm, but please cargo fmt your code, thanks!

Done

[bergwolf]

Still failing. You can run make check locally.

[griff]

I have now run the check locally and fixed the issues found there.

[bergwolf]

@griff

test macfuse_tests::integration_test_macfuse_hello has been running for over 60 seconds

I tried it locally and got the same results. Please help to fix it. You can reproduce by running make smoke-macos locally.