lib/logic_iomem: Fix 32-bit build

On a 32-bit build, the (unsigned long long) casts throw warnings
(or errors) due to being to a different integer size. Cast to
uintptr_t first (with the __force for sparse) and then further
to get the consistent print on 32 and 64-bit.

Fixes: ca2e3342

 ("lib: add iomem emulation (logic_iomem)")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>