pstore/platform: Add check for kstrdup

Add check for the return value of kstrdup() and return the error
if it fails in order to avoid NULL pointer dereference.

Fixes: 563ca40d ("pstore/platform: Switch pstore_info::name to const")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20230623022706.32125-1-jiasheng@iscas.ac.cn


Signed-off-by: Kees Cook <keescook@chromium.org>