virtualbon-ose-kmod build fails with 14-CURRENT and llvm15

I updated my system yesterday. I then tried to rebuild virtualbox-ose-kmod.
This fails under llvm15. The same source code built successfully with
llvm14, so I assume that the code has a problem with 15. I suspect that 15
changed some default and declared this as an error, but may be "fixed" with
the proper build option.

Here is the command and error that I see:

cc  -O2 -pipe -fno-strict-aliasing -DRT_OS_FREEBSD -DIN_RING0 -DIN_RT_R0
-DIN_SUP_R0 -DSUPDRV_WITH_RELEASE_LOGGER -DVBOX -DRT_WITH_VBOX -w
-DVBOX_WITH_HARDENING -DVBOX_WITH_64_BITS_GUESTS -DRT_ARCH_AMD64  -Werror
-D_KERNEL -DKLD_MODULE -nostdinc  -Iinclude -I. -Ir0drv -include
/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-6.1.36/out/freebsd.amd64/release/bin/src/vboxdrv/opt_global.h
-I. -I/usr/src/sys -I/usr/src/sys/contrib/ck/include -fno-common
 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer
-fdebug-prefix-map=./machine=/usr/src/sys/amd64/include
-fdebug-prefix-map=./x86=/usr/src/sys/x86/include
-fdebug-prefix-map=./i386=/usr/src/sys/i386/include     -MD
 -MF.depend.SUPDrv-freebsd.o -MTSUPDrv-freebsd.o -mcmodel=kernel
-mno-red-zone -mno-mmx -mno-sse -msoft-float
 -fno-asynchronous-unwind-tables -ffreestanding -fwrapv -fstack-protector
-Wall -Wnested-externs -Wstrict-prototypes -Wmissing-prototypes
-Wpointer-arith -Wcast-qual -Wundef -Wno-pointer-sign
-D__printf__=__freebsd_kprintf__ -Wmissing-include-dirs
-fdiagnostics-show-option -Wno-unknown-pragmas
-Wno-error=tautological-compare -Wno-error=empty-body
-Wno-error=parentheses-equality -Wno-error=unused-function
-Wno-error=pointer-sign -Wno-error=shift-negative-value
-Wno-address-of-packed-member -Wno-error=array-parameter
-Wno-error=deprecated-non-prototype -Wno-error=strict-prototypes
-Wno-error=unused-but-set-variable -Wno-format-zero-length   -mno-aes
-mno-avx  -std=iso9899:1999 -c
/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-6.1.36/out/freebsd.amd64/release/bin/src/vboxdrv/freebsd/SUPDrv-freebsd.c
-o SUPDrv-freebsd.o
/usr/ports/emulators/virtualbox-ose-kmod/work/VirtualBox-6.1.36/out/freebsd.amd64/release/bin/src/vboxdrv/freebsd/SUPDrv-freebsd.c:433:50:
error: incompatible pointer to integer conversion passing 'void *' to
parameter of type 'RTR3PTR' (aka 'unsigned long') [-Wint-conversion]
        if (RT_FAILURE(RTR0MemUserCopyFrom(&Hdr, pvUser, sizeof(Hdr))))
                                                 ^~~~~~
include/iprt/errcore.h:99:58: note: expanded from macro 'RT_FAILURE'

Any help appreciated. I really need virtualbox. I think I may force it to
build with llvm14, but I's prefer a fix to build with llvm15.

-- 
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683