Don't treat DumpOptions->dump_inserts like a boolean

This has been an integer count since 7e413a0f so treat it explicitly
like an integer.

No backpatch since this is just cosmetic.

src/bin/pg_dump/pg_backup.h

@@ -71,7 +71,7 @@ typedef struct _restoreOptions
 	char	   *use_role;		/* Issue SET ROLE to this */
 	int			dropSchema;
 	int			disable_dollar_quoting;
-	int			dump_inserts;
+	int			dump_inserts;	/* 0 = COPY, otherwise rows per INSERT */
 	int			column_inserts;
 	int			if_exists;
 	int			no_comments;	/* Skip comments */

src/bin/pg_dump/pg_dump.c

@@ -2254,7 +2254,7 @@ dumpTableData(Archive *fout, TableDataInfo *tdinfo)
 	char	   *copyStmt;
 	const char *copyFrom;
 
-	if (!dopt->dump_inserts)
+	if (dopt->dump_inserts == 0)
 	{
 		/* Dump/restore using COPY */
 		dumpFn = dumpTableData_copy;