mxqd: Revert return status of init_child_process

Return 0 on success, -1 on failure.

This change will make the following commit easier to follow.

mxqd.c

@@ -842,7 +842,7 @@ static int init_child_process(struct mxq_group_list *glist, struct mxq_job *job)
     if (!passwd) {
         mx_log_err("job=%s(%d):%lu:%lu getpwuid(): %m",
             group->user_name, group->user_uid, group->group_id, job->job_id);
-        return 0;
+        return -1;
     }
 
     if (!mx_streq(passwd->pw_name, group->user_name)) {
@@ -859,7 +859,7 @@ static int init_child_process(struct mxq_group_list *glist, struct mxq_job *job)
         if (!passwd) {
             mx_log_err("job=%s(%d):%lu:%lu getpwnam(): %m",
                 group->user_name, group->user_uid, group->group_id, job->job_id);
-            return 0;
+            return -1;
         }
         if (passwd->pw_uid != group->user_uid) {
             mx_log_fatal("job=%s(%d):%lu:%lu user_name=%s does not map to uid=%d but to pw_uid=%d. Aborting Child execution.",
@@ -871,7 +871,7 @@ static int init_child_process(struct mxq_group_list *glist, struct mxq_job *job)
                             group->user_uid,
                             passwd->pw_uid);
 
-            return 0;
+            return -1;
         }
     }
 
@@ -881,7 +881,7 @@ static int init_child_process(struct mxq_group_list *glist, struct mxq_job *job)
     if (res != 0) {
         mx_log_err("job=%s(%d):%lu:%lu clearenv(): %m",
             group->user_name, group->user_uid, group->group_id, job->job_id);
-        return 0;
+        return -1;
     }
 
     mx_setenv_forever("USER",     group->user_name);
@@ -933,7 +933,7 @@ static int init_child_process(struct mxq_group_list *glist, struct mxq_job *job)
     if (fh == -1) {
         mx_log_err("job=%s(%d):%lu:%lu open(%s) failed: %m",
             group->user_name, group->user_uid, group->group_id, job->job_id, "/proc/self/loginuid");
-        return 0;
+        return -1;
     }
     dprintf(fh, "%d", group->user_uid);
     close(fh);
@@ -972,39 +972,39 @@ static int init_child_process(struct mxq_group_list *glist, struct mxq_job *job)
     if (res == -1) {
         mx_log_err("job=%s(%d):%lu:%lu initgroups() failed: %m",
             group->user_name, group->user_uid, group->group_id, job->job_id);
-        return 0;
+        return -1;
     }
 
     res = setregid(group->user_gid, group->user_gid);
     if (res == -1) {
         mx_log_err("job=%s(%d):%lu:%lu setregid(%d, %d) failed: %m",
             group->user_name, group->user_uid, group->group_id, job->job_id,
             group->user_gid, group->user_gid);
-        return 0;
+        return -1;
     }
 
     res = setreuid(-1, group->user_uid);
     if (res == -1) {
         mx_log_err("job=%s(%d):%lu:%lu setreuid(%d, %d) failed: %m",
             group->user_name, group->user_uid, group->group_id, job->job_id,
             group->user_uid, group->user_uid);
-        return 0;
+        return -1;
     }
 
     res = chdir(job->job_workdir);
     if (res == -1) {
         mx_log_err("job=%s(%d):%lu:%lu chdir(%s) failed: %m",
             group->user_name, group->user_uid, group->group_id, job->job_id,
             job->job_workdir);
-        return 0;
+        return -1;
     }
 
     umask(job->job_umask);
 
     res=sched_setaffinity(0,sizeof(job->host_cpu_set),&job->host_cpu_set);
     if (res<0) mx_log_warning("sched_setaffinity: $m");
 
-    return 1;
+    return 0;
 }
 
 /**********************************************************************/
@@ -1136,7 +1136,7 @@ static int exec_reaper(struct mxq_server *server,struct mxq_group_list *glist, s
     }
 
     res = init_child_process(glist, job);
-    if (!res)
+    if (res == -1)
         return(-1);
 
     mxq_job_set_tmpfilenames(group, job);