libqmi: fail on positive errors in qmidev_{dis,}connect

dev_open can return positive errors, but qmidev_connect was only failing
on negative errors.

BUG=None
TEST=get_cid_stress_test (to come) no longer hangs

Change-Id: Ia038a0394326fd1806d23f5d60c2f2f5401cfcac
1 file changed
tree: b7d8edd4533ba01728c08b38e5c5d3ebcf380a0f
  1. .gitignore
  2. LICENSE
  3. Makefile
  4. README
  5. include/
  6. src/