parse-util: make parse_fd() return -EBADF

The previous error code -ERANGE is slightly ambiguous, and use more
specific one. This also drops unnecessary error handlings.

Follow-up for 754d8b9c33 and
e652663a04.

src/shared/bpf-program.c

@@ -450,8 +450,6 @@ int bpf_program_deserialize_attachment(const char *v, FDSet *fds, BPFProgram **b
                 return -EINVAL;
 
         ifd = parse_fd(sfd);
-        if (ifd == -ERANGE)
-                return -EBADF;
         if (ifd < 0)
                 return r;
 

src/shared/varlink.c

@@ -3061,9 +3061,6 @@ int varlink_server_deserialize_one(VarlinkServer *s, const char *value, FDSet *f
         buf = strndupa_safe(v, n);
 
         fd = parse_fd(buf);
-        if (fd == -ERANGE)
-                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "VarlinkServerSocket varlink-server-socket-fd= has an invalid value: %s", buf);
         if (fd < 0)
                 return log_debug_errno(fd, "Unable to parse VarlinkServerSocket varlink-server-socket-fd=%s: %m", buf);
         if (!fdset_contains(fds, fd))