NTB: Fix 'request_irq()' and 'free_irq()' inconsistancy

'request_irq()' and 'free_irq()' should have the same 'dev_id'.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>