build_emoji: Remove an unnecessary check for symlink support.

We already check for symlink support in provisioning script so no
need of doing so here.

tools/setup/emoji/build_emoji

@@ -90,13 +90,7 @@ def main():
 
     print("Using cached emojis from {}".format(source_emoji_dump))
     run(['rm', '-rf', TARGET_EMOJI_DUMP])
-    try:
-        os.symlink(
-            source_emoji_dump,
-            TARGET_EMOJI_DUMP
-        )
-    except OSError:
-        print("Error: Unable to create symlinks. Make sure you have permission to create symbolic links.")
+    os.symlink(source_emoji_dump, TARGET_EMOJI_DUMP)
 
 def get_success_stamp():
     # type: () -> str