scsi: use 'depends' instead of 'select' for SCSI_FC_ATTRS

There are other kconfig symbols which use SCSI_FC_ATTRS.
In order to maintain sanity and prevent kconfig warnings, change
all of these from using 'select' to using 'depends on' so that
proper symbol dependencies will be honored and circular depends
problems will be avoided.
This fixes kconfig warnings and build errors:

warning: (LIBFC && SCSI_IBMVFC && SCSI_QLA_FC && SCSI_LPFC && ZFCP && SCSI_BFA_FC && SCSI_CHELSIO_FCOE && FUSION_FC) selects SCSI_FC_ATTRS which has unmet direct dependencies (SCSI && NET)
drivers/scsi/scsi_transport_fc.c: In function 'fc_host_post_event':
drivers/scsi/scsi_transport_fc.c:543:7: error: 'scsi_nl_sock' undeclared (first use in this function)
drivers/scsi/scsi_transport_fc.c: In function 'fc_host_post_vendor_event':
drivers/scsi/scsi_transport_fc.c:611:7: error: 'scsi_nl_sock' undeclared (first use in this function)

Reported-by: Fengguang Wu <fengguang.wu@intel.com> [0-day test robot]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>