Remove some unnecessary includes of "access/xlog_internal.h"

There were a few places where access/xlog_internal.h was apparently
included unnecessarily.  In some of those places, a more specific
header file (that somehow came in via access/xlog_internal.h) can be
used instead.

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/a56a6eec-eb14-471b-9570-3cac23603964%40eisentraut.org

src/bin/pg_checksums/pg_checksums.c

@@ -20,11 +20,11 @@
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "access/xlog_internal.h"
 #include "common/controldata_utils.h"
 #include "common/file_perm.h"
 #include "common/file_utils.h"
 #include "common/logging.h"
+#include "common/relpath.h"
 #include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_getopt.h"

src/bin/pg_rewind/timeline.c

@@ -10,7 +10,6 @@
 #include "postgres_fe.h"
 
 #include "access/timeline.h"
-#include "access/xlog_internal.h"
 #include "pg_rewind.h"
 
 /*

src/include/access/generic_xlog.h

@@ -15,7 +15,7 @@
 #define GENERIC_XLOG_H
 
 #include "access/xlog.h"
-#include "access/xlog_internal.h"
+#include "access/xlogreader.h"
 #include "access/xloginsert.h"
 #include "storage/bufpage.h"
 #include "utils/rel.h"