perf tools: Cast off_t to s64 to avoid warning on bionic libc

To avoid this warning:

CC /tmp/build/perf/util/s390-cpumsf.o
util/s390-cpumsf.c: In function 's390_cpumsf_samples':
util/s390-cpumsf.c:508:3: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 4 has type 'off_t' [-Wformat=]
pr_err("[%#08" PRIx64 "] Invalid AUX trailer entry TOD clock base\n",
^

Now the various Android cross toolchains used in the perf tools
container test builds are all clean and we can remove this:

export EXTRA_MAKE_ARGS="WERROR=0"

Cc: Adrian Hunter <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Thomas Richter <[e-mail]>
Link: https://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/s390-cpumsf.c

···
 	aux_ts = get_trailer_time(buf);
 	if (!aux_ts) {
 		pr_err("[%#08" PRIx64 "] Invalid AUX trailer entry TOD clock base\n",
-		       sfq->buffer->data_offset);
+		       (s64)sfq->buffer->data_offset);
 		aux_ts = ~0ULL;
 		goto out;
 	}