process.c (assert_close_on_exec): quiet warning about unused result

Not much we can do if writing to STDERR_FILENO fails.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63963 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

process.c

@@ -295,7 +295,7 @@ assert_close_on_exec(int fd)
         int flags = fcntl(fd, F_GETFD);
         if (flags == -1) {
                 static const char m[] = "reserved FD closed unexpectedly?\n";
-                write(2, m, sizeof(m) - 1);
+                (void)write(2, m, sizeof(m) - 1);
                 return;
         }
         if (flags & FD_CLOEXEC) return;