unit-test: Fix PEP8 E225 violation

E225: missing whitespace around operator

Change-Id: I10088f5fb77888f26ef9387af123fe82bf22fc80
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/scripts/unit-test.py b/scripts/unit-test.py
index 3f5096e..4378cc7 100755
--- a/scripts/unit-test.py
+++ b/scripts/unit-test.py
@@ -509,7 +509,7 @@
         """
         self.path = "." if not path else path
         self.package = package if package else os.path.basename(os.path.realpath(self.path))
-        self.build_for_testing=False
+        self.build_for_testing = False
 
     def probe(self):
         """Test if the build system driver can be applied to the package