perf daemon: Fix the build on more 32-bit architectures

perf daemon: Fix the build on more 32-bit architectures

FYI: I'm carrying this on perf-tools-next.

The previous attempt fixed the build on debian:experimental-x-mipsel,
but when building on a larger set of containers I noticed it broke the
build on some other 32-bit architectures such as:

  42     7.87 ubuntu:18.04-x-arm            : FAIL gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04)
    builtin-daemon.c: In function 'cmd_session_list':
    builtin-daemon.c:692:16: error: format '%llu' expects argument of type 'long long unsigned int', but argument 4 has type 'long int' [-Werror=format=]
       fprintf(out, "%c%" PRIu64,
                    ^~~~~
    builtin-daemon.c:694:13:
        csv_sep, (curr - daemon->start) / 60);
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In file included from builtin-daemon.c:3:0:
    /usr/arm-linux-gnueabihf/include/inttypes.h:105:34: note: format string is defined here
     # define PRIu64  __PRI64_PREFIX "u"

So lets cast that time_t (32-bit/64-bit) to uint64_t to make sure it
builds everywhere.

Fixes: 4bbe6002931954bb ("perf daemon: Fix the build on 32-bit architectures")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/ZsPmldtJ0D9Cua9_@x1
Signed-off-by: Namhyung Kim <namhyung@kernel.org>