util: lsblk: include command in error string

Previously this would return a string that was missing the
command being executed, for example:

"failed to execute `-dno pkname /dev/sda1`: exit status 32"

Now it will return something like the following, which makes
a bit more sense when read:

"failed to execute `lsblk -dno parttype /dev/sda1`: exit status 32"

Signed-off-by: Tim Serong <tserong@suse.com>

pkg/block/util.go

@@ -74,7 +74,7 @@ func lsblk(devPath, output string) (string, error) {
 	}
 	out, err := exec.Command(LSBLKCMD, args[0:]...).Output() // #nosec G204
 	if err != nil {
-		return "", fmt.Errorf("failed to execute `%s`: %s", strings.Join(args, " "), err.Error())
+		return "", fmt.Errorf("failed to execute `%s %s`: %s", LSBLKCMD, strings.Join(args, " "), err.Error())
 	}
 
 	return strings.TrimSuffix(string(out), "\n"), nil