scripted-diff: Use BlockManager::LookupBlockIndex

[META] In a previous commit, we moved ::LookupBlockIndex to become a
       member function of BlockManager. This commit is split out from
       that one since it can be expressed nicely as a scripted-diff.

-BEGIN VERIFY SCRIPT-
find_regex='LookupBlockIndex' \
    && git grep -l -E "$find_regex" -- src \
        | grep -v '^src/validation\.\(cpp\|h\)$' \
        | xargs sed -i -E "s@${find_regex}@g_chainman.m_blockman.LookupBlockIndex@g"
-END VERIFY SCRIPT-

src/node/coinstats.cpp

@@ -63,7 +63,7 @@ static bool GetUTXOStats(CCoinsView* view, CCoinsStats& stats, T hash_obj, const
     stats.hashBlock = pcursor->GetBestBlock();
     {
         LOCK(cs_main);
-        stats.nHeight = LookupBlockIndex(stats.hashBlock)->nHeight;
+        stats.nHeight = g_chainman.m_blockman.LookupBlockIndex(stats.hashBlock)->nHeight;
     }
 
     PrepareHash(hash_obj, stats);