btrfs: Fix warning "variable ‘gen’ set but not used"

Variable 'gen' in reada_for_search() is not used since commit 58dc4ce43251
("btrfs: remove unused parameter from readahead_tree_block").  This patch
simply removes this variable.

Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

path: root/irq.h

#ifndef IRQ_H
#define IRQ_H

extern int device_irq_number(const char *ifname);
extern void device_restore_irq_affinity_list(void);
extern int device_set_irq_affinity_list(int irq, unsigned long from,
					unsigned long to);
extern int device_set_irq_affinity(int irq, unsigned long cpu);

#endif /* IRQ_H */