perf probe: Use hexadecimal type by default if possible

Use hexadecimal type by default if it is available on current running
kernel.

This keeps the default behavior of perf probe after changing the output
format of 'u8/16/32/64' to unsigned decimal number.

Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Hemant Kumar <[email protected]>
Cc: Naohiro Aota <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/147151074685.12957.16415861010796255514.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: mhiramat

tools/perf/util/probe-finder.c

@@ -373,7 +373,8 @@ static int convert_variable_type(Dwarf_Die *vr_die,
 		 probe_type_is_available(PROBE_TYPE_X))
 		prefix = 'x';
 	else
-		prefix = die_is_signed_type(&type) ? 's' : 'u';
+		prefix = die_is_signed_type(&type) ? 's' :
+			 probe_type_is_available(PROBE_TYPE_X) ? 'x' : 'u';
 
 	ret = dwarf_bytesize(&type);
 	if (ret <= 0)