Fix lp[] initialization

Fix lp[] initialization

Originally, the s variable was a pointer which was allocated with
calloc() every time we went through the loop. Now, it's a stack variable
which gets memset() back to zero instead, and is copied to the array.

This change was done for an unrelated reason (which is why we didn't
change this assignment back then), but with the current code it's more
efficient and less error-prone if we assign values to the pointers when
we declare the lp[] array, rather than when we go through the loop. So
do that, then.