fp-lit-mask: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/lib64/piglit/bin/fp-lit-mask - from package: piglit

You may install the required package with command yum install {package}
Error in other languages:
fp-lit-mask: bevel nie gevind nie
fp-lit-mask: comandă negăsită
fp-lit-mask: comando não encontrado
fp-lit-mask: commande introuvable
fp-lit-mask: command not found
fp-lit-mask: käsku ei ole
fp-lit-mask: không tìm thấy lệnh
fp-lit-mask: komanda nerasta
fp-lit-mask: Kommando nicht gefunden.
fp-lit-mask: kommandot finns inte
fp-lit-mask: komut yok
fp-lit-mask: nie znaleziono polecenia
fp-lit-mask: níor aimsíodh an t-ordú
fp-lit-mask: no se encontró la orden
fp-lit-mask: no s'ha trobat l'ordre
fp-lit-mask: opdracht niet gevonden
fp-lit-mask: parancs nem található
fp-lit-mask: perintah tidak ditemukan
fp-lit-mask: príkaz nenájdený
fp-lit-mask: příkaz nenalezen
fp-lit-mask: команда не найдена
fp-lit-mask: командата не е открита
fp-lit-mask: 命令找不到
fp-lit-mask: コマンドが見つかりません