scsi: lpfc: Check kzalloc() in lpfc_sli4_cgn_params_read()

In the Linux kernel, the following vulnerability has been resolved:

scsi: lpfc: Check kzalloc() in lpfc_sli4_cgn_params_read()

If kzalloc() fails in lpfc_sli4_cgn_params_read(), then we rely on

lpfc_read_object()'s routine to NULL check pdata.

Currently, an early return error is thrown from lpfc_read_object() to

protect us from NULL ptr dereference, but the errno code is -ENODEV.

Change the errno code to a more appropriate -ENOMEM.