Fix printf
diff --git a/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c b/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c
index d31d463..bb44321 100644
--- a/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c
+++ b/src/core/lib/iomgr/ev_epoll_thread_pool_linux.c
@@ -1167,7 +1167,8 @@
EPS_ADD_REF(eps, "fd");
fd->eps = eps;
- GRPC_POLLING_TRACE("add_fd_to_eps (fd: %d, eps idx = %ld)", fd->fd, idx);
+ GRPC_POLLING_TRACE("add_fd_to_eps (fd: %d, eps idx = %" PRIdPTR ")", fd->fd,
+ idx);
gpr_mu_unlock(&fd->mu);
GRPC_LOG_IF_ERROR("add_fd_to_eps", error);