Fix compiler warning:

../src/btree/rec_evict.c: In function '__rec_review':
../src/btree/rec_evict.c:1040:26: error: conversion to 'uint32_t' from 'int' may change the sign of the result [-Werror=sign-conversion]
       WT_EVICTION_LOCKED | (top &&
                          ^
Fix a bug where we were attempting to free an invalid block.
Run forced eviction even if updates can't be included.

We support writing out partial pages now, so we can make progress regardless.