Staging: comedi: Fix some raw printks with dev_warn()

Brought to you with the help of sed and manual clean-up after.

  $ sed -i -e 's|printk("\\n|dev_warn(dev->hw_dev,\n\t"|' \
    addi-data/hwdrv_apci1500.c

Since all of these printk()s were for invalid API inputs and most of
them returned -EINVAL, I fixed the rest of them to return -EINVAL as
well.
Signed-off-by: Conrad Meyer <cse.cem@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>