fix line length

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/scripts/depends.py b/tests/scripts/depends.py
index a7d5672..25a15c4 100755
--- a/tests/scripts/depends.py
+++ b/tests/scripts/depends.py
@@ -381,7 +381,8 @@
 
     def __init__(self, options, conf):
         """Gather data about the library and establish a list of domains to test."""
-        build_command = [options.make_command] + options.make_vars.split(' ') + ['CFLAGS=-Werror -O2']
+        build_command = [options.make_command] + options.make_vars.split(' ') + \
+            ['CFLAGS=-Werror -O2']
         build_and_test = [build_command, [options.make_command, 'test']]
         self.all_config_symbols = set(conf.settings.keys())
         # Find hash modules by name.