Bug 1271084 - Apply ESLint autofixes to ignored /devtools files. r=tromey

For simple rules like function spacing, we can auto-fix these across the code
base so they are followed in a consistent way.

To generate this patch, I ran:

./mach eslint devtools --no-ignore --fix

After this, I reverted any changes to third party files that we really do want
to ignore.

MozReview-Commit-ID: 6Q8BApkAW20

devtools/client/framework/toolbox-init.js

@@ -51,7 +51,7 @@ if (url.search.length > 1) {
         DebuggerServer.addBrowserActors();
       }
       let client = new DebuggerClient(DebuggerServer.connectPipe());
-      Task.spawn(function*() {
+      Task.spawn(function* () {
         yield client.connect();
         // Creates a target for a given browser iframe.
         let response = yield client.getTab({ tab });