mmc: toshsd: fix return value check of mmcaddhost()
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v4.9.337 by commit 34ae492f8d172f0bd193c24cad588b35419ea47a, it was introduced in version v3.19 by commit a5eb8bbd66ccf9f169419f9652544aec771b7c57. For more details please see the references link.