Documentation: Fix a typo in an environment variable name.
Should be XDG_CACHE_HOME, not XDG_CACHE_DIR.
@@ -22,7 +22,7 @@ pocl.
If this is set to an existing directory, pocl uses it as the cache
directory for all compilation results. This allows reusing compilation
results between pocl invocations. If this env is not set, then the
- default cache directory will be used, which is ``$XDG_CACHE_DIR/pocl/kcache``
+ default cache directory will be used, which is ``$XDG_CACHE_HOME/pocl/kcache``
(if set) or ``$HOME/.cache/pocl/kcache/`` on Unix-like systems.
- **POCL_DEBUG**
