In ata_host_alloc(), if devres_alloc() fails to allocate the device host
resource data pointer, the already allocated ata_host structure is not
freed before returning from the function. This results in a potential
memory leak.

Call kfree(host) before jumping to the error handling path to ensure
that the ata_host structure is properly freed if devres_alloc() fails.

Fixes: 2623c7a5 ("libata: add refcounting to ata_host")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>