rmlint: fails to build on arm{el,hf}: undefined reference to `rm_xattr_is_deduplicated'

[bdrung]

rmlint: fails to build on arm{el,hf}: undefined reference to rm_xattr_is_deduplicated:

gcc -o rmlint -Wl,-z,relro -Wl,-z,now -pthread src/rmlint.o librmlint.a -lblkid -ljson-glib-1.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0 -lelf -lm -lelf
/usr/bin/ld: librmlint.a(session.o): in function `rm_session_dedupe_main':
./lib/session.c:227:(.text+0x79c): undefined reference to `rm_xattr_is_deduplicated'
/usr/bin/ld: ./lib/session.c:345:(.text+0xaf4): undefined reference to `rm_xattr_mark_deduplicated'
collect2: error: ld returned 1 exit status
scons: *** [rmlint] Error 1

This happens for cases where xattr support is missing (i.e. HAVE_XATTR is not defined).

See https://buildd.debian.org/status/fetch.php?pkg=rmlint&arch=armel&ver=2.9.0-2.5%2Bb1&stamp=1710031282&raw=0

Bug-Debian: https://bugs.debian.org/1065947
Bug-Ubuntu: https://launchpad.net/bugs/2066970

[fazalmajid]

Should be fixed by #605