configfs: Correct error value returned by API config_item_set_name()

kvasprintf() failure is often caused by memory allocation which has error
code -ENOMEM, but config_item_set_name() returns -EFAULT for the failure.

Fix by returning -ENOMEM instead of -EFAULT for the failure.

Reviewed-by: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250507-fix_configfs-v3-3-fe2d96de8dc4@quicinc.com


Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>