Replace qemu_pipe() with g_unix_open_pipe()

GLib g_unix_open_pipe() is essentially like qemu_pipe(), available since
2.30.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

include/qemu/osdep.h

@@ -547,10 +547,6 @@ static inline void qemu_timersub(const struct timeval *val1,
 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
     G_GNUC_WARN_UNUSED_RESULT;
 
-#ifndef _WIN32
-int qemu_pipe(int pipefd[2]);
-#endif
-
 void qemu_set_cloexec(int fd);
 
 /* Return a dynamically allocated directory path that is appropriate for storing

qemu-nbd.c

@@ -909,13 +909,14 @@ int main(int argc, char **argv)
 
     if ((device && !verbose) || fork_process) {
 #ifndef WIN32
+        g_autoptr(GError) err = NULL;
         int stderr_fd[2];
         pid_t pid;
         int ret;
 
-        if (qemu_pipe(stderr_fd) < 0) {
+        if (!g_unix_open_pipe(stderr_fd, FD_CLOEXEC, &err)) {
             error_report("Error setting up communication pipe: %s",
-                         strerror(errno));
+                         err->message);
             exit(EXIT_FAILURE);
         }
 

util/event_notifier-posix.c

@@ -49,7 +49,7 @@ int event_notifier_init(EventNotifier *e, int active)
         if (errno != ENOSYS) {
             return -errno;
         }
-        if (qemu_pipe(fds) < 0) {
+        if (!g_unix_open_pipe(fds, FD_CLOEXEC, NULL)) {
             return -errno;
         }
         if (!g_unix_set_fd_nonblocking(fds[0], true, NULL)) {

util/oslib-posix.c

@@ -274,28 +274,6 @@ void qemu_set_cloexec(int fd)
     assert(f != -1);
 }
 
-/*
- * Creates a pipe with FD_CLOEXEC set on both file descriptors
- */
-int qemu_pipe(int pipefd[2])
-{
-    int ret;
-
-#ifdef CONFIG_PIPE2
-    ret = pipe2(pipefd, O_CLOEXEC);
-    if (ret != -1 || errno != ENOSYS) {
-        return ret;
-    }
-#endif
-    ret = pipe(pipefd);
-    if (ret == 0) {
-        qemu_set_cloexec(pipefd[0]);
-        qemu_set_cloexec(pipefd[1]);
-    }
-
-    return ret;
-}
-
 char *
 qemu_get_local_state_dir(void)
 {