Fix trailing whitespace

Signed-off-by: Werner Lewis <werner.lewis@arm.com>
diff --git a/scripts/mbedtls_dev/test_generation.py b/scripts/mbedtls_dev/test_generation.py
index b22d58f..2981a74 100644
--- a/scripts/mbedtls_dev/test_generation.py
+++ b/scripts/mbedtls_dev/test_generation.py
@@ -166,7 +166,7 @@
     parser.add_argument('--directory', default="tests/suites", metavar='DIR',
                         help='Output directory (default: tests/suites)')
     parser.add_argument('targets', nargs='*', metavar='TARGET',
-                        default=sorted(generator_class.TARGETS), 
+                        default=sorted(generator_class.TARGETS),
                         help='Target file to generate (default: all; "-": none)')
     options = parser.parse_args(args)
     build_tree.chdir_to_root()