glx: Remove unused bswap_CARD64
GCC warned about it:
../../../glx/indirect_dispatch_swap.c:85:1: warning: ‘bswap_CARD64’ defined but not used [-Wunused-function]
85 | bswap_CARD64(const void *src)
| ^~~~~~~~~~~~
GCC warned about it:
../../../glx/indirect_dispatch_swap.c:85:1: warning: ‘bswap_CARD64’ defined but not used [-Wunused-function]
85 | bswap_CARD64(const void *src)
| ^~~~~~~~~~~~