phy: phy-rockchip-inno-usb2: Handle failed extcon allocation better

phy: phy-rockchip-inno-usb2: Handle failed extcon allocation better

Return the actual error code upon failure to allocate extcon device, instead
of hardcoding -ENOMEM.  Use dev_err_probe() to also log appropriate messages,
which is fine because the containing function is used in the probe path.

Helped-by: Heiko Stubner <heiko@sntech.de>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Link: https://lore.kernel.org/r/cc4995aa3e569be6bc23ca126b41fba82d50eeee.1725524802.git.dsimic@manjaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>