HID: bpf: fix gcc warning and unify __u64 into u64

I've got multiple reports of:
error: cast from pointer to integer of different size
[-Werror=pointer-to-int-cast].

Let's use the same trick than kernel/bpf/helpers.c to shut up that warning.

Even if we were on an architecture with addresses on more than 64 bits,
this isn't much of an issue as the address is not used as a pointer,
but as an hash and the caller is not supposed to go back to the kernel
address ever.

And while we change those, make sure we use u64 instead of __u64 for
consistency

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406280633.OPB5uIFj-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406282304.UydSVncq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406282242.Fk738zzy-lkp@intel.com/


Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Fixes: 67eccf15 ("HID: add source argument to HID low level functions")
Link: https://patch.msgid.link/20240701-fix-cki-v2-2-20564e2e1393@kernel.org


Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>