Patch for coverity issue:

    https://cov01.lab.eng.brq.redhat.com/el8-results/el8/libdb-5.3.28-31.el8+7/scan-results-imp.html#def141

diff -up db-5.3.28/src/os/os_flock.c.add_sys_file_h db-5.3.28/src/os/os_flock.c

--- db-5.3.28/src/os/os_flock.c.add_sys_file_h	2019-02-11 10:17:20.575939063 +0100

+++ db-5.3.28/src/os/os_flock.c	2019-02-11 10:17:41.037243374 +0100

@@ -9,6 +9,7 @@

 #include "db_config.h"

 #include "db_int.h"

+#include <sys/file.h>

 #if !defined(HAVE_FCNTL) || !defined(HAVE_FLOCK)

 static int __os_filelocking_notsup __P((ENV *));