servo: Merge #14829 - Fix browserhtml path (from Wafflespeanut:browserhtml); r=UK992

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I'd missed something in #14817, which now prevents us from running `./mach run -r -b`. @UK992 pointed this in the PR, but it got merged soon 😐

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

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- [x] These changes do not require tests because it's a fix for mach

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Source-Repo: https://github.com/servo/servo
Source-Revision: 128aac921f4373b618418125ea6f7c6ac3797181

servo/python/servo/post_build_commands.py

@@ -98,7 +98,7 @@ class PostBuildCommands(CommandBase):
         args = [self.get_binary_path(release, dev)]
 
         if browserhtml:
-            browserhtml_path = get_browserhtml_path('browserhtml', args[0])
+            browserhtml_path = get_browserhtml_path(args[0])
             if is_macosx():
                 # Enable borderless on OSX
                 args = args + ['-b']
@@ -109,7 +109,7 @@ class PostBuildCommands(CommandBase):
             args = args + ['--pref', 'dom.mozbrowser.enabled',
                            '--pref', 'dom.forcetouch.enabled',
                            '--pref', 'shell.builtin-key-shortcuts.enabled=false',
-                           path.join(browserhtml_path, 'out', 'index.html')]
+                           path.join(browserhtml_path, 'index.html')]
 
         if headless:
             set_osmesa_env(args[0], env)