math: fix i386/expl.s with more precise x*log2e
[musl] / arch /
drwxr-xr-x   ..
drwxr-xr-x - arm
drwxr-xr-x - i386
drwxr-xr-x - microblaze
drwxr-xr-x - mips
drwxr-xr-x - powerpc
drwxr-xr-x - x86_64