swrast: Fix -Wduplicate-decl-specifier warning
swrast: Fix -Wduplicate-decl-specifier warning

swrast.c:67:12: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
const char const *swrast_vendor_string = "Mesa Project";
           ^
swrast.c:68:12: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
const char const *swrast_renderer_string = "Software Rasterizer";
           ^

Signed-off-by: Jeremy Huddleston Sequoia <db3cec0cba09acb9cf8fd8bd399a3b27498cf883@apple.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler