glx: Fix unused-variable warning with macOS build.
../src/glx/tests/indirect_api.cpp:52:20: warning: unused variable 'nil' [-Wunused-variable] static const void *nil = 0; ^
Signed-off-by: Vinson Lee vlee@freedesktop.org
../src/glx/tests/indirect_api.cpp:52:20: warning: unused variable 'nil' [-Wunused-variable] static const void *nil = 0; ^
Signed-off-by: Vinson Lee vlee@freedesktop.org