button: qcom-pmic: Fix dereference of uninitialised pointer

button: qcom-pmic: Fix dereference of uninitialised pointer

The pointer 'label' is declared and later dereferenced without ever
having a value assigned to it. Add an assignment to this pointer so it
will be valid later when dereferenced.

This issue was found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Casey Connolly <casey.connolly@linaro.org>
Link: https://lore.kernel.org/r/20250723-button-qcom-pmic-v1-1-9c317ac71167@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>