package/kodi/br-kodi: fix shellcheck SC2086

Shellcheck 0.9.0 now report SC2086:

In package/kodi/br-kodi line 38:
exit ${ret}
     ^----^ SC2086 (info): Double quote to prevent globbing and word splitting.

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/kodi/br-kodi

@@ -35,4 +35,4 @@ while [ ${LOOP} -eq 1 ]; do
             ;;
     esac
 done
-exit ${ret}
+exit "${ret}"