exit(2) on unsupported positional arguments on command line

Change-Id: I6d4efa6ddef41607aecd5ceee78e400db821292f
diff --git a/src/e1_recorder.c b/src/e1_recorder.c
index 9110ccb..d085ca5 100644
--- a/src/e1_recorder.c
+++ b/src/e1_recorder.c
@@ -123,6 +123,11 @@
 			break;
 		}
 	}
+
+	if (argc > optind) {
+		fprintf(stderr, "Unsupported positional arguments on command line\n");
+		exit(2);
+	}
 }
 
 int main(int argc, char **argv)