syndaemon: list -? in help/man page

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

man/syndaemon.man

@@ -61,6 +61,10 @@ Like \-k but also ignore Modifier+Key combos.
 \fB\-R\fP
 Use the XRecord extension for detecting keyboard activity instead of polling
 the keyboard state.
+.LP
+.TP
+\fB\-?\fP
+Show the help message.
 .SH "ENVIRONMENT VARIABLES"
 .LP
 .TP

tools/syndaemon.c

@@ -88,6 +88,7 @@ usage(void)
     fprintf(stderr, "  -K Like -k but also ignore Modifier+Key combos.\n");
     fprintf(stderr, "  -R Use the XRecord extension.\n");
     fprintf(stderr, "  -v Print diagnostic messages.\n");
+    fprintf(stderr, "  -? Show this help message.\n");
     exit(1);
 }
 
@@ -576,6 +577,7 @@ main(int argc, char *argv[])
         case 'v':
             verbose = 1;
             break;
+        case '?':
         default:
             usage();
             break;