[SCSI] qla2xxx: Change del_timer_sync() to del_timer() in qla2x00_ctx_sp_free().

Using del_timer_sync() in the qla2x00_ctx_sp_free() function may cause a kernel
panic as it is not interrupt context safe and qla2x00_ctx_sp_free() may be
called from a softirq context.  Changing the call from del_timer_sync() to
del_timer() will make the function interrupt context safe.

Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Madhuranath Iyengar <Madhu.Iyengar@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>