error: New qemu_opts_loc_restore()

Needed for decent error locations when complaining about options
outside of qemu_opts_foreach().  That one sets the location
already.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qemu-option.c b/qemu-option.c
index 30327d4..1f8f41a 100644
--- a/qemu-option.c
+++ b/qemu-option.c
@@ -728,6 +728,11 @@
     }
 }
 
+void qemu_opts_loc_restore(QemuOpts *opts)
+{
+    loc_restore(&opts->loc);
+}
+
 int qemu_opts_set(QemuOptsList *list, const char *id,
                   const char *name, const char *value)
 {