Don't leak file descriptors

We're leaking file descriptors to child processes. Set FD_CLOEXEC on file
descriptors that don't need to be passed to children to stop this misbehaviour.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

gdbstub.c

@@ -2356,6 +2356,9 @@ static void gdb_accept(void)
             perror("accept");
             return;
         } else if (fd >= 0) {
+#ifndef _WIN32
+            fcntl(fd, F_SETFD, FD_CLOEXEC);
+#endif
             break;
         }
     }
@@ -2385,6 +2388,9 @@ static int gdbserver_open(int port)
         perror("socket");
         return -1;
     }
+#ifndef _WIN32
+    fcntl(fd, F_SETFD, FD_CLOEXEC);
+#endif
 
     /* allow fast reuse */
     val = 1;