doc fix for ratbag_unref
doc fix for ratbag_unref

Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

NoXPhasma/libratbag,libratbag/libratbag,NoXPhasma/libratbag,NoXPhasma/libratbag,whot/libratbag,cvuchener/libratbag,libratbag/libratbag,cvuchener/libratbag,whot/libratbag,cvuchener/libratbag,libratbag/libratbag,whot/libratbag