Add exch timeout info to have debug log with exch timeout
value to match with retries, also add debug info
on exch timer cancel.

Added common fc_exch_timer_cancel() func and grouped this
along with fc_exch_timer_set() function, so that
added debug code is not repeated.
Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>