So the word llama originates from latin roots and in spanish a double L is pronounced as a Y. So in spanish its pronounced "Yama" but in English it's pronounced "Lama". There is no need for an extra L (it would still be pronounced the same). We don't even identify which one of the L's are silent. Its unnecessary. 

     On a complete side note I've made a bet with my best friend that if i can legally change Llama to Lama, she'll legit buy me a Llama (or should i say Lama).