Fix regression bug regarding locking

If get_dbf_head() failed the database file was not unlocked, what could
cause deadlocks on Windows.

git-svn-id: http://svn.php.net/repository/pecl/dbase/trunk@340807 c90b9560-bf6c-de11-be94-00142212c4b1

Author: cmb69

dbf_head.c

@@ -285,6 +285,8 @@ dbhead_t *dbf_open(char *dp, int o_flags)
 	}
 
 	if ((dbh = get_dbf_head(fd)) ==	NULL) {
+		php_flock(fd, LOCK_UN);
+		close(fd);
 		return NULL;
 	}