(partially) Fix Bug#55227 Fix compiler warnings in innodb with gcc 4.6

Fix compiler warning:
btr/btr0sea.c: In function 'btr_search_update_hash_on_delete':
btr/btr0sea.c:1498:9: error: variable 'found' set but not used [-Werror=unused-but-set-variable]

storage/innodb_plugin/btr/btr0sea.c

@@ -1495,7 +1495,6 @@ btr_search_update_hash_on_delete(
 	rec_t*		rec;
 	ulint		fold;
 	dulint		index_id;
-	ibool		found;
 	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
 	mem_heap_t*	heap		= NULL;
 	rec_offs_init(offsets_);
@@ -1528,7 +1527,7 @@ btr_search_update_hash_on_delete(
 	}
 	rw_lock_x_lock(&btr_search_latch);
 
-	found = ha_search_and_delete_if_found(table, fold, rec);
+	ha_search_and_delete_if_found(table, fold, rec);
 
 	rw_lock_x_unlock(&btr_search_latch);
 }