Correct spelling, explanation: this is the correct spelling because there is only one l at the end (there is no need to double the last consonant of the word if it’s the last letter). Therefore controll is incorrect, and probably this mistake comes from the fact, that l is doubled with suffixes, for example controlling.

Definition of control:
noun, the power to direct what others do
Who is in control of this restaurant?
verb, supervise
I control my feelings much better after taking up therapy.

Idioms and phrases with control:
control freak, a person who is obsessed with having everything under their control
Sarah can’t share her duties with anyone, she’s a huge control freak.
be out of control, be reckless, become impossible to control
The car was out of control and crashed into a tree.

Incorrect spelling, explanation: spelling control with double l (controll) is incorrect because there is no reason to double the last consonant at the end of the word. L would be doubled in case of adding some suffix but the bare word doesn’t need it. Therefore control is the correct spelling.