perf ui helpline: Provide a printf variant

To print some values, like in the annotation code with invalid jump
offsets.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-1vk0g5twas2ioswn1mmvnvwq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/helpline.h

@@ -21,6 +21,7 @@ void ui_helpline__push(const char *msg);
 void ui_helpline__vpush(const char *fmt, va_list ap);
 void ui_helpline__fpush(const char *fmt, ...);
 void ui_helpline__puts(const char *msg);
+void ui_helpline__printf(const char *fmt, ...);
 int  ui_helpline__vshow(const char *fmt, va_list ap);
 
 extern char ui_helpline__current[512];