On 64-bit Linux systems, if LD_PRELOAD isn't a relative/absolute
pathname to libswmhack.so, then ld.so attempts to load a 32-bit version
for 32-bit programs. This produces an error message. The solution is
to either build and install a 32-bit libswmhack.so.0.0 or use an
absolute/relative path so that ld.so only loads libswmhack.so for 64-bit
binaries.
Fix Makefiles to set variables before they are referenced.