.so.x.y passed to PR_LoadLibrary() is never the same as the one on
linux, since the portstree controls the .x.y, so if the first dlopen()
fails, let's strip what's after .so and retry, since ld.so is clever
enough to open the correct lib if asked for libfoo.so. Allows me to
remove smth like 40 patches in all mozilla ports. Take maintainership
while here.
discussed with deraadt@
