kunit: tool: make --raw_output=kunit (aka --raw_output) preserve leading spaces

With
$ kunit.py run --raw_output=all ...
you get the raw output from the kernel, e.g. something like
> TAP version 14
> 1..26
> # Subtest: time_test_cases
> 1..1
> ok 1 - time64_to_tm_test_date_range
> ok 1 - time_test_cases

But --raw_output=kunit or equivalently --raw_output, you get
> TAP version 14
> 1..26
> # Subtest: time_test_cases
> 1..1
> ok 1 - time64_to_tm_test_date_range
> ok 1 - time_test_cases

It looks less readable in my opinion, and it also isn't "raw output."

This is due to sharing code with kunit_parser.py, which wants to strip
leading whitespace since it uses anchored regexes.
We could update the kunit_parser.py code to tolerate leaading spaces,
but this patch takes the easier way out and adds a bool flag.

Signed-off-by: Daniel Latypov <[e-mail]>
Reviewed-by: David Gow <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/kunit/kunit.py

···
 		if request.raw_output == 'all':
 			pass
 		elif request.raw_output == 'kunit':
-			output = kunit_parser.extract_tap_lines(output)
+			output = kunit_parser.extract_tap_lines(output, lstrip=False)
 		for line in output:
 			print(line.rstrip())
 

tools/testing/kunit/kunit_parser.py

···
 KTAP_END = re.compile('(List of all partitions:|'
 	'Kernel panic - not syncing: VFS:|reboot: System halted)')
 
-def extract_tap_lines(kernel_output: Iterable[str]) -> LineStream:
+def extract_tap_lines(kernel_output: Iterable[str], lstrip=True) -> LineStream:
 	"""Extracts KTAP lines from the kernel output."""
 	def isolate_ktap_output(kernel_output: Iterable[str]) \
 			-> Iterator[Tuple[int, str]]:
···
 				# stop extracting KTAP lines
 				break
 			elif started:
-				# remove prefix and any indention and yield
-				# line with line number
-				line = line[prefix_len:].lstrip()
+				# remove the prefix and optionally any leading
+				# whitespace. Our parsing logic relies on this.
+				line = line[prefix_len:]
+				if lstrip:
+					line = line.lstrip()
 				yield line_num, line
 	return LineStream(lines=isolate_ktap_output(kernel_output))