adbd: don't spin if file sync read fails.

Bug: http://b/64508974
Bug: 64709603 (presubmit balking at the line above)
Test: mma
Change-Id: Ifba6a9dea3138b6d2a62c91cc0532f63986c048a
(cherry picked from commit 645cd7053c9fffc5a5378ed0a743715e87e07211)
1 file changed