Fix warnings

drivers/net/davinci_emac.c: In function 'emac_p_write_stats':
drivers/net/davinci_emac.c:2732: warning: ignoring return value of
'copy_from_user', declared with attribute warn_unused_result
drivers/net/davinci_emac.c: In function 'emac_dev_open':
drivers/net/davinci_emac.c:3517: warning: 'deprecated_irq_flag' is
deprecated (declared at include/linux/interrupt.h:66)
drivers/net/davinci_emac.c: In function 'emac_dev_probe':
drivers/net/davinci_emac.c:6804: warning: ignoring return value of
'driver_create_file', declared with attribute warn_unused_result
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Kevin Hilman <khilman@mvista.com>