scripts: kconfig: optimize write_kconfig_filenames

Filter duplicate entries in `kconf.kconfig_filenames` before calling
`os.path.realpath`.

Before (current code), all entries in `kconf.kconfig_filenames` go
through `os.path.realpath`. Including all duplicate entries.

With the proposed change, the duplicate entries are removed before
calling `os.path.realpath`.

Signed-off-by: Guðni Már Gilbert <[email protected]>

Author: gudnimg

scripts/kconfig/kconfig.py

@@ -294,7 +294,7 @@ def write_kconfig_filenames(kconf, kconfig_list_path):
 
     with open(kconfig_list_path, 'w') as out:
         for path in sorted({os.path.realpath(os.path.join(kconf.srctree, path))
-                            for path in kconf.kconfig_filenames}):
+                            for path in set(kconf.kconfig_filenames)}):
             print(path, file=out)