xen-mfndump: Use inttypes.h to format uint64_t types.

xen-mfndump: Use inttypes.h to format uint64_t types.

Fixes 32-bit build:

cc1: warnings being treated as errors
xen-mfndump.c: In function 'dump_ptes_func':
xen-mfndump.c:236: error: format '%lx' expects type 'long unsigned int', but argument 3 has type 'uint64_t'
xen-mfndump.c: In function 'lookup_pte_func':
xen-mfndump.c:305: error: format '%lx' expects type 'long unsigned int', but argument 5 has type 'uint64_t'

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>