Merge "Report errno more often in fastboot." am: 8c5384e50b am: 272b2694cd am: 7f80f04a2c
am: b2c88646dd

* commit 'b2c88646ddcae33c5a0992d37ac30dffd2d019f4':
  Report errno more often in fastboot.

Change-Id: I62e87f56cbceb9238adc5fd7306950092f547139