perf tools: Fix perf's libperf_print callback

eprintf() does not expect va_list as the type of the 4th parameter.

Use veprintf() because it does.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: 428dab81

 ("libperf: Merge libperf_set_print() into libperf_init()")
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220408132625.2451452-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>