unit-test: Fix PEP8 E231 violation

E231: missing whitespace after ','

Change-Id: I8922d445ab6a673a05d38e5b2dae1e9389699b27
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/scripts/unit-test.py b/scripts/unit-test.py
index 4378cc7..da576a0 100755
--- a/scripts/unit-test.py
+++ b/scripts/unit-test.py
@@ -335,7 +335,7 @@
             # Dependency package not added
             new_child = dep_tree.AddChild(dep)
             dep_added[dep] = False
-            dep_pkgdir = clone_pkg(dep,branch)
+            dep_pkgdir = clone_pkg(dep, branch)
             # Determine this dependency package's
             # dependencies and add them before
             # returning to add this package