[PATCH RESEND 15/25] mpt3sas: Refcount fw_events and fix unsafe list usage

From: Sreekanth Reddy The fw_event_work struct is concurrently referenced at shutdown, so add a refcount to protect it, and refactor the code to use it. Additionally, refactor _scsih_fw_event_cleanup_queue() such that it no longer iterates over the list without holding the lock, since

[PATCH RESEND 15/25] mpt3sas: Refcount fw_events and fix unsafe list usage

From: Sreekanth Reddy The fw_event_work struct is concurrently referenced at shutdown, so add a refcount to protect it, and refactor the code to use it. Additionally, refactor _scsih_fw_event_cleanup_queue() such that it no longer iterates over the list without