typo

doc/doxygen/chapters/501_environment_variables.doxy

@@ -52,7 +52,7 @@ Specify the number of workers per CUDA device, and thus the number of kernels
 which will be concurrently running on the devices. The default value is 1.
 </dd>
 
-<dt>STARPU_NWORKER_PER_CUDA</dt>
+<dt>STARPU_CUDA_THREAD_PER_WORKER</dt>
 <dd>
 \anchor STARPU_CUDA_THREAD_PER_WORKER
 \addindex __env__STARPU_CUDA_THREAD_PER_WORKER