[PULL 3/4] qga: Improve error report by calling error_setg_win32()

[Markus Armbruster <armbru@redhat.com>]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Use error_setg_win32() which adds a hint similar to strerror(errno)).

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200228100726.8414-4-philmd@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 qga/channel-win32.c  | 3 ++-
 qga/commands-win32.c | 8 +++++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/qga/channel-win32.c b/qga/channel-win32.c
index c86f4388db..99648c95b6 100644
--- a/qga/channel-win32.c
+++ b/qga/channel-win32.c
@@ -308,7 +308,8 @@ static gboolean ga_channel_open(GAChannel *c, GAChannelMethod method,
     }
 
     if (method == GA_CHANNEL_ISA_SERIAL && !SetCommTimeouts(c->handle,&comTimeOut)) {
-        g_critical("error setting timeout for com port: %lu",GetLastError());
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        g_critical("error setting timeout for com port: %s", emsg);
         CloseHandle(c->handle);
         return false;
     }
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 2461fd19bf..9c744d6405 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -315,8 +315,9 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
     }
 
     if (!ExitWindowsEx(shutdown_flag, SHTDN_REASON_FLAG_PLANNED)) {
-        slog("guest-shutdown failed: %lu", GetLastError());
-        error_setg(errp, QERR_UNDEFINED_ERROR);
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        slog("guest-shutdown failed: %s", emsg);
+        error_setg_win32(errp, GetLastError(), "guest-shutdown failed");
     }
 }
 
@@ -1319,7 +1320,8 @@ static DWORD WINAPI do_suspend(LPVOID opaque)
     DWORD ret = 0;
 
     if (!SetSuspendState(*mode == GUEST_SUSPEND_MODE_DISK, TRUE, TRUE)) {
-        slog("failed to suspend guest, %lu", GetLastError());
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        slog("failed to suspend guest: %s", emsg);
         ret = -1;
     }
     g_free(mode);
-- 
2.21.1