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

* commit '272b2694cd3556120a3e39b88a0702103e2ed58a':
  Report errno more often in fastboot.

Change-Id: Ie26d2c70e65b70c08017f848f21fb91d6f20e3a4