io_spec.c: suppress unused-variable warning

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58731 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/rubyspec/optional/capi/ext/io_spec.c

@@ -11,13 +11,13 @@ extern "C" {
 #endif
 
 static int set_non_blocking(int fd) {
-  int flags;
 #if defined(O_NONBLOCK) && defined(F_GETFL)
-  if (-1 == (flags = fcntl(fd, F_GETFL, 0)))
+  int flags = fcntl(fd, F_GETFL, 0);
+  if (flags == -1)
     flags = 0;
   return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
 #elif defined(FIOBIO)
-  flags = 1;
+  int flags = 1;
   return ioctl(fd, FIOBIO, &flags);
 #else
   errno = ENOSYS;