dem_kfree() is called from all over the place and should actually
do something;  contrary to lkpi_devm_kmalloc_release() it can also
take a const void *.  We have to __DECONST() that though as the
entire devres framework does otherwise not take a const argument.
This was discovered during the rtw89 upadte to 6.16.
Sponsored by:	The FreeBSD Foundation
MFC after:	3 days