[Samba] [samba] cross compile

[锦城吴]

Hi, All,
I compiled the Samba-4.8.4 on armv7-gcc success, but the smbclient can't be
work well because the linux of device is in-deep customization.
I should modify some code in the part of create socket. So, my question is
how to add CFLAGS when compile libinterfaces-samba4.so?

I already add code to samba/lib/socket/interfaces.c but the compile happen
error cause of undefined reference to `deep-in-socket-create`, and I
already add "-ldeep-in-sock" to CFLAGS.

It seems like the CFLAGS doesn't work when compile lib.

Hope you can help me fix the problems, thanks a lot.