src: remove return after abort
Refs https://github.com/electron/electron/pull/36818.
This extra return
causes a build failure in Electron:
../../third_party/electron_node/src/node_builtins.cc:250:5: error: 'return' will never be executed [-Werror,-Wunreachable-code-return]
return;
^~~~~~
1 error generated.