fix python format

Author: keith

llvm/utils/lit/lit/TestRunner.py

@@ -1227,8 +1227,10 @@ def executeScript(test, litConfig, tmpBase, commands, cwd):
         if test.config.pipefail:
             f.write(b"set -o pipefail;" if mode == "wb" else "set -o pipefail;")
 
-        env_str = "\n".join("export {}={};".format(k, shlex.quote(v))
-                            for k, v in test.config.environment.items())
+        env_str = "\n".join(
+            "export {}={};".format(k, shlex.quote(v))
+            for k, v in test.config.environment.items()
+        )
         f.write(bytes(env_str, "utf-8") if mode == "wb" else env_str)
         f.write(b"set -x;" if mode == "wb" else "set -x;")