mm/memblock.c: replace u64 with phys_addr_t where appropriate

Most functions in memblock already use phys_addr_t to represent a
physical address with __memblock_free_late() being an exception.

This patch replaces u64 with phys_addr_t in __memblock_free_late() and
switches several format strings from %llx to %pa to avoid casting from
phys_addr_t to u64.

Link: http://lkml.kernel.org/r/1530637506-1256-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>