drm/pseudofs panic with drm-515-kmod

See

https://lists.freebsd.org/archives/freebsd-current/2025-May/007756.html

for a kernel panic stack trace.

Short story world and drm-515-kmod were working fine with src/
and ports/ trees circa February 2025.  Updated both src/ and
ports/ via 'git pull -ff'.  Performed the standard rebuilding
procedure for src/ and installed a new world.  I then rebuilt
drm-515-kmod and the gpu-firmare.  System reboots fine.  The
console changes from a large font with ~80 characters per line
to a tiny font with ~132 chars/line.  Upon execution of startx
to load Xorg and fvwm2, I get a panic.  The back trace shows

#5  0xffffffff805c8718 in pfs_add_node (
     parent=parent@entry=0xfffff80003955400, pn=pn@entry=0xfffff803557e0900)
     at /usr/src/sys/fs/pseudofs/pseudofs.c:123
         iter = <optimized out>
#6  0xffffffff805c8bd2 in pfs_create_file (parent=0xfffff80003955400,
     name=name@entry=0xffffffff82b293f4 "radeon_ring_gfx",
     fill=0xffffffff82bf70f0 <debugfs_fill>,
     attr=0xffffffff82bf72f0 <debugfs_attr>, vis=vis@entry=0x0,
     destroy=0xffffffff82bf7310 <debugfs_destroy>, flags=33)
     at /usr/src/sys/fs/pseudofs/pseudofs.c:266
         pn = 0xfffff803557e0900
#7  0xffffffff82bf70b8 in debugfs_create_file (
     name=0xffffffff82b293f4 "radeon_ring_gfx", mode=292,
     parent=0xfffff8000398e400, data=0xfffffe012354dd30,
     fops=0xffffffff82b55918 <radeon_debugfs_ring_info_fops>)
     at /usr/src/sys/compat/lindebugfs/lindebugfs.c:209
         dm = 0xfffff80003990580
         dnode = 0xfffff80003990580
         pnode = <unavailable>
         flags = <optimized out>
         _size = <optimized out>
         _malloc_item = <optimized out>
#8  0xffffffff82ad0084 in radeon_ring_init () from 
/boot/modules/radeonkms.ko
No symbol table info available.

--
Steve