qemu-sockets: do not test path with access() before unlinking

qemu-sockets: do not test path with access() before unlinking

Using access() is a time-of-check/time-of-use race condition.  It is
okay to use them to provide better error messages, but that is pretty
much it.

This is not one such case; on the other hand, access() *will* skip
unlink() for a non-existent path, so ignore ENOENT return values from
the unlink() system call.

Signed-off-by: Paolo Bonzini <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Reviewed-by: Edgar E. Iglesias <[email protected]>
Signed-off-by: Michael Tokarev <[email protected]>