[ Upstream commit 7c0195fa9a9e263df204963f88a22b21688ffb66 ] devm_kstrdup() returns pointer to allocated string on success, NULL on failure. So it is better to check the return value of it. Fixes: e35478eac030 ("i2c: mux: demux-pinctrl: run properly with multiple instances") Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com> Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>