binman: Fix IFWI output when using an Intel FIT image

At present this entry does not work correctly when a FIT image is used as
the input. It updates the FIT instead of the output image. The test passed
because the FIT image happened to have the right data already.

Fix it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/binman/ftest.py b/tools/binman/ftest.py
index 080599f..bba07e7 100644
--- a/tools/binman/ftest.py
+++ b/tools/binman/ftest.py
@@ -2044,7 +2044,7 @@
                           subpart='IBBP', entry_name='IBBL')
 
         tpl_data = tools.ReadFile(tpl_fname)
-        self.assertEqual(tpl_data[:len(U_BOOT_TPL_DATA)], U_BOOT_TPL_DATA)
+        self.assertEqual(U_BOOT_TPL_DATA, tpl_data[:len(U_BOOT_TPL_DATA)])
 
     def testPackX86RomIfwi(self):
         """Test that an x86 ROM with Integrated Firmware Image can be created"""