call wants args to be in an array

Author: Mike Dirolf

SConstruct

@@ -1656,7 +1656,7 @@ def build_and_test_client(env, target, source):
     from subprocess import call
 
     if GetOption("extrapath") is not None:
-        call("scons --extrapath=%s" % GetOption("extrapath"), cwd=installDir)
+        call(["scons", "--extrapath=" + GetOption("extrapath")], cwd=installDir)
     else:
         call("scons", cwd=installDir)
     return bool(call(["python", "buildscripts/smoke.py",