chg: dev: Check that coverage data was generated
chg: dev: Check that coverage data was generated

Some processes may fail to produce any coverage data during
test run, this change verifies that data was generated before
attempting to produce a coverage report.

Change-Id: I438620ff1c4e40c77aa1197964611b9a84b59121
Signed-off-by: Walinton Cambronero <1f04f885082cc0892df9219a8132f4f8086a7db5@hpe.com>

open-switch/infra_project-config,open-switch/infra_project-config