[physfs] Error when compiling PhysicsFS

[Ryan C. Gordon]

> [ 98%] Built target physfs-static
> make[2]: *** No rule to make target `libphysfs.so', needed by
> `test_physfs'.  Stop.

I think this was a cmake bug that was fixed later than what Suse ships.

For now, build like this:

   cd /where/i/downloaded/physfs
   cmake -DPHYSFS_BUILD_TEST=False -DPHYSFS_BUILD_WX_TEST=False .
   make

--ryan.