fix a flake8 lint

Summary: fix a lint, platform variable was declared twice

Reviewed By: Croohand

Differential Revision: D32605614

fbshipit-source-id: 8e43de8689bf30410273355444db9c3d94663d43

build/fbcode_builder/getdeps/builder.py

@@ -726,8 +726,6 @@ if __name__ == "__main__":
             # better signals for flaky tests.
             retry = 0
 
-        from sys import platform
-
         testpilot = path_search(env, "testpilot")
         tpx = path_search(env, "tpx")
         if (tpx or testpilot) and not no_testpilot: