lr(0): remove useless conditional

[Akim Demaille]

commit 5670677cb697aa79fef15978dd880ec2b40dbab3
Author: Akim Demaille <akim.demai...@gmail.com>
Date:   Tue Jan 29 06:36:41 2019 +0100

    lr(0): remove useless conditional
    
    * src/lr0.c (new_itemsets): There's no harm in setting a Boolean
    several times.

diff --git a/src/lr0.c b/src/lr0.c
index 9d8d3d55..fa982b5c 100644
--- a/src/lr0.c
+++ b/src/lr0.c
@@ -185,9 +185,7 @@ new_itemsets (state *s)
     if (item_number_is_symbol_number (ritem[itemset[i]]))
       {
         symbol_number sym = item_number_as_symbol_number (ritem[itemset[i]]);
-        if (!kernel_size[sym])
-          bitset_set (shift_symbol, sym);
-
+        bitset_set (shift_symbol, sym);
         kernel_base[sym][kernel_size[sym]] = itemset[i] + 1;
         kernel_size[sym]++;
       }