fsm_test.c: fix unreachable check

Change-Id: Ic3d5da00f7ece6dbcd4c999187a5748c9331e60f
diff --git a/tests/fsm/fsm_test.c b/tests/fsm/fsm_test.c
index eea8b22..3bcb7d4 100644
--- a/tests/fsm/fsm_test.c
+++ b/tests/fsm/fsm_test.c
@@ -95,8 +95,10 @@
 static struct ctrl_cmd *exec_ctrl_cmd(const char *cmdstr)
 {
 	struct ctrl_cmd *cmd;
-	return ctrl_cmd_exec_from_string(g_ctrl, cmdstr);
+
+	cmd = ctrl_cmd_exec_from_string(g_ctrl, cmdstr);
 	OSMO_ASSERT(cmd);
+
 	return cmd;
 }