mmc: vub300: 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 41ed46bdbd2878cd6567abe0974a445f8b1b8ec8, it was introduced in version v3.0 by commit 88095e7b473a3d9ec3b9c60429576e9cbd327c89. For more details please see the references link.