scripts: twister: Fix return value for size

If size is given then twister prnits the size information for the ELF
but returns one which if used in automation fails the command.

Return zero as the command is successful. Also, fix the unit test case.

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>

scripts/pylib/twister/twisterlib/environment.py

@@ -745,7 +745,7 @@ def parse_arguments(parser, args, options = None):
         for fn in options.size:
             sc = SizeCalculator(fn, [])
             sc.size_report()
-        sys.exit(1)
+        sys.exit(0)
 
     if len(options.extra_test_args) > 0:
         # extra_test_args is a list of CLI args that Twister did not recognize

scripts/tests/twister/test_environment.py

@@ -190,7 +190,7 @@ def test_parse_arguments_errors_size():
         with pytest.raises(SystemExit) as exit_info:
             twisterlib.environment.parse_arguments(parser, args)
 
-    assert exit_info.value.code == 1
+    assert exit_info.value.code == 0
 
     mock_calc_parent.child.assert_has_calls([mock.call(('dummy.elf', []), {})])
     mock_calc_parent.child().size_report.assert_has_calls([mock.call()])