MFC r297873

1. Process tx completions in bxe_periodic_callout_func() and restart transmissions if possible.
2. For SIOCSIFFLAGS call bxe_init_locked() only if !BXE_STATE_DISABLED
3. remove code not needed in bxe_init_internal_common()

Submitted by:vaishali.kulkarni@qlogic.com;venkata.bhavaraju@qlogic.com