systemc: Fix a typo in verify.py.

In the generic (non-console output) output checker, a variable should
have been called self.test, but was called self.text.

Change-Id: I2518d6ff01c51fc195eef2b61e987d1b3104c89b
Reviewed-on: https://gem5-review.googlesource.com/c/12817
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/tests/verify.py

@@ -198,7 +198,7 @@ class Checker(object):
         self.tag = tag
 
     def check(self):
-        with open(self.text) as test_f, open(self.ref) as ref_f:
+        with open(self.test) as test_f, open(self.ref) as ref_f:
             return test_f.read() == ref_f.read()
 
 def tagged_filt(tag, num):