This reverts commit 6f9d2080.

6f9d2080 was committed to work around a Nvidia driver bug that can cause vkGetRandROutputDisplayEXT()
to generate an X exception and crash applications. The bug is later fixed in Nvidia driver 450.56.11
and newer. Thus 6f9d2080 is no longer necessary on the newer Nvidia drivers.

Then after 18ae96e5, another bug in the Nvidia driver can cause vkGetRandROutputDisplayEXT() to hang
forever when XLockDisplay() is called before vkGetRandROutputDisplayEXT() and this bug is still not
fixed and affects multiple applications. Reverting 6f9d2080 allows us to work around the
vkGetRandROutputDisplayEXT() hang bug because then it no longer calls XLockDisplay() before
vkGetRandROutputDisplayEXT().

Nvidia driver 455 was released on September 9th 2020 so hopefully the fix is already widespread. We
could theoretically still keep 6f9d2080 on older Nvidia drivers by doing version checks. But it's
more straightforward to remove the workaround since it's not a bug of Wine.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=53428