Windows/DirectIOFile: Don't request DELETE access for read-only Open

Aside from being unnecessary, on Windows the flag prevents two instances
of Dolphin (one instance from before 2509-371 when the flag was
introduced and the other after) from running the same ROM
simultaneously.

Attempting to do so generated the false error `"[Rom]" is an invalid
GCM/ISO file, or is not a GC/Wii ISO.` followed by `Failed to init core`
and emulation shutdown on the second instance to start the game. Fixing
the incorrect error message is a task I'm deferring to another PR.

The problem didn't happen when both instances were 2509-371 or later,
but I ran into it while bisecting an issue and it'd be nice to avoid
that problem in the future.

0 files changed, 0 insertions, 0 deletions