disk: Drop debug messages in part_efi

disk: Drop debug messages in part_efi

This is monstrously verbose when something goes wrong. It should work by
recording the problem and reporting it (once) at the command level. At
present it sometimes outputs hundreds of lines of CRC mismatches.

For now, just silence it all.

  GUID Partition Table Entry Array CRC is wrong: 0xaebfebf2 != 0xc916f712
  find_valid_gpt: *** ERROR: Invalid GPT ***
  find_valid_gpt: ***        Using Backup GPT ***
  GUID Partition Table Entry Array CRC is wrong: 0xaebfebf2 != 0xc916f712
  find_valid_gpt: *** ERROR: Invalid GPT ***
  find_valid_gpt: ***        Using Backup GPT ***
  ...

While we are error, remove the '*** ERROR: ' text as it is already clear
that this is unexpected

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>