io: remove checking of EWOULDBLOCK

Since we now canonicalize WSAEWOULDBLOCK into EAGAIN there is
no longer any need to explicitly check EWOULDBLOCK for Win32.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

io/channel-command.c

@@ -236,8 +236,7 @@ static ssize_t qio_channel_command_readv(QIOChannel *ioc,
  retry:
     ret = readv(cioc->readfd, iov, niov);
     if (ret < 0) {
-        if (errno == EAGAIN ||
-            errno == EWOULDBLOCK) {
+        if (errno == EAGAIN) {
             return QIO_CHANNEL_ERR_BLOCK;
         }
         if (errno == EINTR) {
@@ -265,8 +264,7 @@ static ssize_t qio_channel_command_writev(QIOChannel *ioc,
  retry:
     ret = writev(cioc->writefd, iov, niov);
     if (ret <= 0) {
-        if (errno == EAGAIN ||
-            errno == EWOULDBLOCK) {
+        if (errno == EAGAIN) {
             return QIO_CHANNEL_ERR_BLOCK;
         }
         if (errno == EINTR) {

io/channel-file.c

@@ -96,8 +96,7 @@ static ssize_t qio_channel_file_readv(QIOChannel *ioc,
  retry:
     ret = readv(fioc->fd, iov, niov);
     if (ret < 0) {
-        if (errno == EAGAIN ||
-            errno == EWOULDBLOCK) {
+        if (errno == EAGAIN) {
             return QIO_CHANNEL_ERR_BLOCK;
         }
         if (errno == EINTR) {
@@ -125,8 +124,7 @@ static ssize_t qio_channel_file_writev(QIOChannel *ioc,
  retry:
     ret = writev(fioc->fd, iov, niov);
     if (ret <= 0) {
-        if (errno == EAGAIN ||
-            errno == EWOULDBLOCK) {
+        if (errno == EAGAIN) {
             return QIO_CHANNEL_ERR_BLOCK;
         }
         if (errno == EINTR) {

io/channel-socket.c

@@ -466,8 +466,7 @@ static ssize_t qio_channel_socket_readv(QIOChannel *ioc,
  retry:
     ret = recvmsg(sioc->fd, &msg, sflags);
     if (ret < 0) {
-        if (socket_error() == EAGAIN ||
-            socket_error() == EWOULDBLOCK) {
+        if (socket_error() == EAGAIN) {
             return QIO_CHANNEL_ERR_BLOCK;
         }
         if (socket_error() == EINTR) {
@@ -526,8 +525,7 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
  retry:
     ret = sendmsg(sioc->fd, &msg, 0);
     if (ret <= 0) {
-        if (socket_error() == EAGAIN ||
-            socket_error() == EWOULDBLOCK) {
+        if (socket_error() == EAGAIN) {
             return QIO_CHANNEL_ERR_BLOCK;
         }
         if (socket_error() == EINTR) {