depends.py: set unique configuration names in outcome file

Set unique configuration names in the outcome file. This was lost in the
rewrite from depends-*.pl to depends.py.

Fix #7290

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/depends.py b/tests/scripts/depends.py
index 1a84531..1990cd2 100755
--- a/tests/scripts/depends.py
+++ b/tests/scripts/depends.py
@@ -199,7 +199,10 @@
         success = True
         for command in self.commands:
             log_command(command)
-            ret = subprocess.call(command)
+            env = os.environ.copy()
+            if 'MBEDTLS_TEST_CONFIGURATION' in env:
+                env['MBEDTLS_TEST_CONFIGURATION'] += '-' + self.name
+            ret = subprocess.call(command, env=env)
             if ret != 0:
                 if command[0] not in ['make', options.make_command]:
                     log_line('*** [{}] Error {}'.format(' '.join(command), ret))