HSI: omap_ssi: Don't jump to free ID in ssi_add_controller()

In current code, it jumps to ida_simple_remove() when ida_simple_get()
failes to allocate an ID. Just return to fix it.

Fixes: 0fae1989

 ("HSI: omap_ssi: built omap_ssi and omap_ssi_port into one module")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>