Ignore chars if they are not UTF-8

Signed-off-by: Luke Mondy <luke.mondy@data61.csiro.au>

libsel4test/tools/extract_results.py

diff --git a/libsel4test/tools/extract_results.py b/libsel4test/tools/extract_results.py
index 8cc9b0a..ea36113 100755
--- a/libsel4test/tools/extract_results.py
+++ b/libsel4test/tools/extract_results.py
@@ -66,7 +66,7 @@
 def main():
     parser = argparse.ArgumentParser('Cleanup messy XML output from sel4test')
     parser.add_argument('input',
-                        nargs='?', help='Input file', type=argparse.FileType('r'),
+                        nargs='?', help='Input file', type=argparse.FileType('r', errors="ignore"),
                         default=sys.stdin)
     parser.add_argument('output',
                         nargs='?', help='Output file', type=argparse.FileType('w'),