Fix a bug in the installer

sbin/install.sh

@@ -14,14 +14,14 @@ _log_file='/dev/null'
 
 centos_release=$(cat /etc/centos-release)
 case "${centos_release}" in
-    CentOS Linux release 6.*)
+    "CentOS Linux release 6."*)
         syvinit_script='/etc/init.d/save_io_stats'
         if [[ ! -f "${syvinit_script}" ]]; then
             _log 1 "Installing System V init script"
             cat "${_share_dir}/sysvinit/save_io_stats" >"${syvinit_script}"
         fi
         ;;
-    CentOS Linux release 7.*)
+    "CentOS Linux release 7."*)
         systemd_service_config='/etc/systemd/system/save_io_stats.service'
         if [[ ! -f "${systemd_service_config}" ]]; then
             _log 1 "Installing systemd service configuration file"