scsi: mvsas: replace kfree with scsi_host_put

The return value of scsi_host_alloc() should be released by
scsi_host_put(). However, in function mvs_pci_init(), kfree()
is used. This patch replaces kfree() with scsi_host_put() to avoid
possible memory leaks.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Reviewed-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>