Bug#44521 Prepared Statement: CALL p() - crashes: `! thd->main_da.is_sent' failed et.al.

Fixed wrong prototype declaration which cased build failure on solaris.

libmysqld/emb_qcache.h

@@ -79,4 +79,4 @@ class Querycache_stream
 uint emb_count_querycache_size(THD *thd);
 int emb_load_querycache_result(THD *thd, Querycache_stream *src);
 void emb_store_querycache_result(Querycache_stream *dst, THD* thd);
-void net_send_eof(THD *thd, uint server_status, uint total_warn_count);
+bool net_send_eof(THD *thd, uint server_status, uint total_warn_count);