Fix device name completion for 'eject'

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/monitor.c b/monitor.c
index 362322b..08a9ea5 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3062,6 +3062,9 @@
             }
         }
         str = args[nb_args - 1];
+        if (*ptype == '-' && ptype[1] != '\0') {
+            ptype += 2;
+        }
         switch(*ptype) {
         case 'F':
             /* file completion */