Don't bother cleaning the hash before an error

Author: aitap

src/rbindlist.c

@@ -439,7 +439,7 @@ SEXP rbindlist(SEXP l, SEXP usenamesArg, SEXP fillArg, SEXP idcolArg, SEXP ignor
               if (tt==NULL) {
                 // # nocov start
                 // C spec states that if realloc() fails (above) the original block (levelsRaw) is left untouched: it is not freed or moved. We ...
-                for (int k=0; k<nLevel; k++) hash_set(marks, levelsRaw[k], 0);   // ... rely on that in this loop which uses levelsRaw.
+                // ... rely on that by freeing levelsRaw.
                 free(levelsRaw);
                 error(_("Failed to allocate working memory for %d factor levels of result column %d when reading item %d of item %d"), allocLevel, idcol+j+1, w+1, i+1);
                 // # nocov end