scripts: gen_kobject_placeholders: iterating the dictionary directly

Fix:
************* Module gen_kobject_placeholders
scripts/gen_kobject_placeholders.py:88:19: C0201:
Consider iterating the dictionary directly
instead of calling .keys() (consider-iterating-dictionary)

Signed-off-by: Julien Massot <julien.massot@iot.bzh>

scripts/gen_kobject_placeholders.py

@@ -85,7 +85,7 @@ def generate_linker_headers(obj):
             continue
 
         name = one_sect.name
-        if name in sections.keys():
+        if name in sections:
             # Need section alignment and size
             sections[name]['align'] = one_sect['sh_addralign']
             sections[name]['size'] = one_sect['sh_size']