Ignore return value of function declared with 'warn_unused_result' (p…

…ytorch#84369)

Summary:
Pull Request resolved: pytorch#84369

X-link: pytorch/multipy#152

Ignore return value of function declared with 'warn_unused_result'

Addresses the following build failure that we get on some of our internal build environments:
caffe2/torch/csrc/deploy/environment.h:60:5: error: ignoring return value of function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result] system(rmCmd.c_str());

Test Plan: Successful build

Reviewed By: jiyuanzFB, PaliC

Differential Revision: D39181069

fbshipit-source-id: e571b09c6da9ca3dcac2b5eaf9f8a3f8473adefd

torch/csrc/deploy/environment.h

@@ -57,7 +57,7 @@ class Environment {
   }
   virtual ~Environment() {
     auto rmCmd = fmt::format("rm -rf {}", extraPythonLibrariesDir_);
-    system(rmCmd.c_str());
+    (void)system(rmCmd.c_str());
   }
   virtual void configureInterpreter(Interpreter* interp) = 0;
   virtual const std::vector<std::string>& getExtraPythonPaths() {