[Rd] Compile error when configured with (PR#13256)

[jon at epcc.ed.ac.uk]

Full_Name: Jon Hill
Version: 2.8.1
OS: Linux
Submission from: (NULL) (129.215.63.157)


A semicolon is missing from src/main/platform.c line 1657

#ifdef Unix
# ifdef HAVE_X11
    int X11 = NA_LOGICAL;
# else
    int X11 = FALSE   <--- missing ;
# endif
#endif

Results in a build error when compiling with no X11 libs, i.e. when configured
using:
./configure --with-x=no