sunos: remove futimes() macro

Remove a macro from src/unix/internal.h that aliases futimes() to
futimesat(). Deal with the platform inconsistency in src/unix/fs.c.

src/unix/fs.c

@@ -176,7 +176,11 @@ skip:
   tv[0].tv_usec = (unsigned long)(req->atime * 1000000) % 1000000;
   tv[1].tv_sec  = req->mtime;
   tv[1].tv_usec = (unsigned long)(req->mtime * 1000000) % 1000000;
+# if defined(__sun)
+  return futimesat(req->file, NULL, tv);
+# else
   return futimes(req->file, tv);
+# endif
 #else
   errno = ENOSYS;
   return -1;

src/unix/internal.h

@@ -39,7 +39,6 @@
 #if defined(__sun)
 # include <sys/port.h>
 # include <port.h>
-# define futimes(fd, tv) futimesat(fd, (void*)0, tv)
 #endif /* __sun */
 
 #if defined(__APPLE__) && !TARGET_OS_IPHONE