qemu-char: Print strerror message on failure

The only way for chardev drivers to communicate an error was to return a NULL
pointer, which resulted in an error message that said _that_ something went
wrong, but not _why_.

This patch changes the interface to return 0/-errno and updates
qemu_chr_open_opts to use strerror to display a more helpful error message.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/msmouse.h b/hw/msmouse.h
index 456cb21424..8b853b35bf 100644
--- a/hw/msmouse.h
+++ b/hw/msmouse.h
@@ -1,2 +1,2 @@
 /* msmouse.c */
-CharDriverState *qemu_chr_open_msmouse(QemuOpts *opts);
+int qemu_chr_open_msmouse(QemuOpts *opts, CharDriverState **_chr);