rlimit-util: use read_full_file() for /proc/PID/limits

This one uses "seq_file", i.e. normal FILE stream just works.

src/basic/rlimit-util.c

@@ -471,12 +471,12 @@ int pid_getrlimit(pid_t pid, int resource, struct rlimit *ret) {
         const char *p = procfs_file_alloca(pid, "limits");
         _cleanup_free_ char *limits = NULL;
 
-        r = read_full_virtual_file(p, &limits, NULL);
+        r = read_full_file(p, &limits, /* ret_size = */ NULL);
         if (r < 0)
                 return -EPERM; /* propagate original permission error if we can't access the limits file */
 
         _cleanup_strv_free_ char **l = NULL;
-        l = strv_split(limits, "\n");
+        l = strv_split_newlines(limits);
         if (!l)
                 return -ENOMEM;