Fix MSVC build

libretro-common/include/gfx/gl_capabilities.h

@@ -47,8 +47,6 @@ enum gl_capability_enum
    GL_CAPS_GLES3_SUPPORTED
 };
 
-RETRO_BEGIN_DECLS
-
 bool gl_check_error(char **error_string);
 
 bool gl_query_core_context_in_use(void);
@@ -59,6 +57,4 @@ void gl_query_core_context_unset(void);
 
 bool gl_check_capability(enum gl_capability_enum enum_idx);
 
-RETRO_END_DECLS
-
 #endif