Do not expect fail in cpu test default configuration

Previous CPU test relied on either missing default named.conf or the
missing permissions to write into its default directory. In short that
default configuration would be unusable with current user. It would hang
indefinitely at cpu test if the named user could write into directory
specified in default configuration.

Change it instead to explicitly try non-existent configuration file.
It will still fail immediately, but will not rely on running user or
presence of file at default configuration file path.

(cherry picked from commit 8e789ea62f)

bin/tests/system/cpu/tests.sh

@@ -54,7 +54,8 @@ ret=0
 for cpu in $(cpulist); do
   n=$((n + 1))
   echo_i "testing that limiting CPU sets to 0-${cpu} works ($n)"
-  cpulimit 0 "$cpu" "$NAMED" -g >named.run.$n 2>&1 || true
+  # intentionally fail running the named, but print number of detected cpus during it
+  cpulimit 0 "$cpu" "$NAMED" -g -c missing.conf >named.run.$n 2>&1 || true
   ncpus=$(sed -ne 's/.*found \([0-9]*\) CPU.*\([0-9]*\) worker thread.*/\1/p' named.run.$n)
   [ "$ncpus" -eq "$((cpu + 1))" ] || ret=1
 done