MIPS: APRP: Fix an issue when device_create() fails.

If a call to device_create() fails for a channel during the initialize
loop, we need to clean the devices entries already created before
leaving.

Signed-off-by: Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: Qais Yousef <Qais.Yousef@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: Jerome Oufella <jerome.oufella@savoirfairelinux.com>
Patchwork: https://patchwork.linux-mips.org/patch/7111/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>