test: virsh-optparse: Fix expected test output with new error checking

Commit 4f4c3b13 added code to remember errors during freeing
of domain objects. This changed the output when testing scaled numbers
parsing in virsh-optparse. Adjust the expected output.

tests/virsh-optparse

@@ -212,6 +212,7 @@ compare exp-err err || fail=1
 # Numeric value with invalid suffix
 cat <<\EOF > exp-err || framework_failure
 error: Scaled numeric value '42WB' for <size> option is malformed or out of range
+error: invalid argument: unknown suffix 'WB'
 EOF
 virsh -q -c $test_url setmaxmem test 42WB >out 2>err && fail=1
 test -s out && fail=1