pybootchartgui: Adopt the width of the index in split output files

Add minimum width zero-padding to the index used in split output files
with -s and -o. I.e., if -s 200 is used, then the index will be
zero-padded to three digits width.

(From OE-Core rev: 45565b24651ab502ae49dc49261dc3ad5634191f)

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/pybootchartgui/pybootchartgui/main.py.in

@@ -155,11 +155,13 @@ def main(argv=None):
 			filename = _get_filename(options.output)
 			res_list = parsing.split_res(res, options.num)
 			n = 1
+			width = len(str(len(res_list)))
+			s = "_%%0%dd." % width
 			for r in res_list:
 				if len(res_list) == 1:
 					f = filename + "." + options.format
 				else:
-					f = filename + "_" + str(n) + "." + options.format
+					f = filename + s % n + options.format
 					n = n + 1
 				def render():
 					batch.render(writer, r, options, f)