cmd/govulncheck/integration/k8s: count only called vulnerabilities
cmd/govulncheck/integration/k8s: count only called vulnerabilities

Due to a bug recently addressed, govulncheck was reporting all detected
symbols, not just the called ones. This resulted in wrong expectations
that got broken after the fix was introduced.

Change-Id: I36a60b529c9ea12bb42f055ee0830554183ca11b
Reviewed-on: https://go-review.googlesource.com/c/vuln/+/407054
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Jonathan Amsterdam <e3d3698b2ccd5955e4adf250d0785062d0f9018b@google.com>
Run-TryBot: Zvonimir Pavlinovic <490af24f3def1258d2f7e9b10b20e341f6c68320@google.com>

golang/vuln,golang/vuln