emulators/virtualbox-ose*: Fix mistake in patch

In the commit to update virtualbox-ose to 6.1.28 I made a one line
mistake when reapplying a patch which failed to apply as is.

In the patch
files/patch-src_VBox_HostDrivers_Support_freebsd_SUPDrv-freebsd.c
I did not replay a part removing the line:

rc = copyout(pHdr, pvUser, cbOut);

which was rewriting some data that it should not. The correct code
was anyway present after this leftover statement.

This error made virtualbox log a lot of warnings about Bad CPU
context like this:

vboxdrv: Bad CPU context error at line 373 in SUPDrv-freebsd.c:
ulCmd=0x2000568a: 0x282->0x287!

These seem to be unharmful, but anyway indicate a problem that this
commit fixes.

Reported by: Kevin Oberman <rkoberman@gmail.com> (via mailing list)
Fixes: a3db7da59f9498