[master] 522fcc577 mgt_jail: Fail if jail init fails

[Nils Goroll]

commit 522fcc5775d53bf02f21f6991760f569a0fe73a6
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Fri Feb 14 10:52:07 2025 +0100

    mgt_jail: Fail if jail init fails
    
    Previously, we would fail at a later point with a confusing error message:
    
    Error: linux jail: Could not disable Transparent Hugepage: Invalid argument (22)
    Error:
    Running VCC-compiler failed, signal 11
    VCL compilation failed
    
    (note: EINVAL was injected for testing)

diff --git a/bin/varnishd/mgt/mgt_jail.c b/bin/varnishd/mgt/mgt_jail.c
index 6d7971052..62e3967f7 100644
--- a/bin/varnishd/mgt/mgt_jail.c
+++ b/bin/varnishd/mgt/mgt_jail.c
@@ -109,7 +109,8 @@ VJ_Init(const char *j_arg)
 			ARGV_ERR("-j argument is empty\n");
 		vjt = MGT_Pick(vj_choice, av[1], "jail");
 		CHECK_OBJ_NOTNULL(vjt, JAIL_TECH_MAGIC);
-		(void)vjt->init(av + 2);
+		if (vjt->init(av + 2))
+			ARGV_EXIT;
 		VAV_Free(av);
 	} else {
 		/*