file_cache: avoid double unlock in error handling code
file_cache: avoid double unlock in error handling code

add_cb() shouldn't unlock the node lock since the caller already does that
on error.

Signed-off-by: Josef 'Jeff' Sipek <a620f141433c70aa9e43778305a6c68cbfadfb25@josefsipek.net>


jeffpc/blahgd,jeffpc/blahgd