intel/stub_gpu: Don't run program again after using GDB

Fixes: c56dd678e48 ("intel/stub_gpu: add an option to launch valgrind")
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23736>
1 file changed