bfa: fix leak of bfad_im_port_index on module unload

Resources allocated within bfad_im_port_index idr are not deallocated
on module unload. The patch adds idr_destroy() in exit function.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

drivers/scsi/bfa/bfad_im.c

@@ -851,6 +851,8 @@ bfad_im_module_exit(void)
 
 	if (bfad_im_scsi_vport_transport_template)
 		fc_release_transport(bfad_im_scsi_vport_transport_template);
+
+	idr_destroy(&bfad_im_port_index);
 }
 
 void