Input: iqs5xx - preserve bootloader errors

Input: iqs5xx - preserve bootloader errors

After user space writes the fw_file attribute to push new firmware
to the device, the driver calls iqs5xx_dev_init() to re-initialize
the device with the updated firmware or recover the device in case
the update failed.

In the case of the latter, however, iqs5xx_fw_file_write() returns
zero (success) so long as iqs5xx_dev_init() does not fail, and any
error encountered during the update process is lost. Solve this by
saving the error before calling iqs5xx_dev_init().

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/1611002626-5889-3-git-send-email-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>