iio: ina2xx: give the capture kthread a more useful name string.

iio: ina2xx: give the capture kthread a more useful name string.

  PID  PPID USER     STAT   VSZ %VSZ %CPU COMMAND
  144     2 root     DW       0   0%  33% [ina226:1-8800us]
  141     2 root     DW       0   0%  25% [ina226:0-8800us]
   40     2 root     SW       0   0%  15% [irq/156-4802a00]
  147     2 root     DW       0   0%   7% [ina226:2-8800us]
  145     1 root     S     1236   0%   6% dd if /dev/iio:device1 of /dev/null
  148     1 root     S     1236   0%   4% dd if /dev/iio:device2 of /dev/null
  149   137 root     R     1244   0%   3% top -d 1
  142     1 root     S     1236   0%   2% dd if /dev/iio:device0 of /dev/null

Signed-off-by: Marc Titinger <mtitinger@baylibre.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>