Fix factual and grammatical errors in comments for struct _tableInfo.

Amit Langote, further adjusted by me

src/bin/pg_dump/pg_dump.h

@@ -213,11 +213,11 @@ typedef struct _tableInfo
 	bool		rowsec;			/* is row security enabled? */
 	bool		forcerowsec;	/* is row security forced? */
 	bool		hasoids;		/* does it have OIDs? */
-	uint32		frozenxid;		/* for restore frozen xid */
-	uint32		minmxid;		/* for restore min multi xid */
-	Oid			toast_oid;		/* for restore toast frozen xid */
-	uint32		toast_frozenxid;	/* for restore toast frozen xid */
-	uint32		toast_minmxid;	/* for restore toast min multi xid */
+	uint32		frozenxid;		/* table's relfrozenxid */
+	uint32		minmxid;		/* table's relminmxid */
+	Oid			toast_oid;		/* toast table's OID, or 0 if none */
+	uint32		toast_frozenxid;	/* toast table's relfrozenxid, if any */
+	uint32		toast_minmxid;	/* toast table's relminmxid */
 	int			ncheck;			/* # of CHECK expressions */
 	char	   *reloftype;		/* underlying type for typed table */
 	/* these two are set only if table is a sequence owned by a column: */