staging: bcm2835-camera: Refactored get_format function

Now, when the condition inside the for is fulfilled, I return the result,
instead of checking afterwards whether the counter has reached or not
the end of the list.

Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>