Revert "Amend configure script to support lndir build tree"
This appears to inexplicably break the OS X build, which fails with:
make: *** No rule to make target `utils/unlit/fs.c', needed by `utils/unlit/dist/build/.depend.c_asm'. Stop. make: *** Waiting for unfinished jobs.... make: *** [all] Error 2
This reverts commit 8ee9c574a6d2105ace858f0fee31750acafe0a0f.