pg_dump: Fix inconsistent sscanf() conversions

It was using %u to read a string that was earlier produced by snprintf with %d
into a signed integer variable.  This seems to work in practice but is
incorrect.

found by cppcheck

src/bin/pg_dump/pg_backup_custom.c

@@ -871,7 +871,7 @@ _MasterEndParallelItem(ArchiveHandle *AH, TocEntry *te, const char *str, T_Actio
 	/* no parallel dump in the custom archive */
 	Assert(act == ACT_RESTORE);
 
-	sscanf(str, "%u %u %u%n", &dumpId, &status, &n_errors, &nBytes);
+	sscanf(str, "%d %d %d%n", &dumpId, &status, &n_errors, &nBytes);
 
 	Assert(nBytes == strlen(str));
 	Assert(dumpId == te->dumpId);

src/bin/pg_dump/pg_backup_directory.c

@@ -859,14 +859,14 @@ _MasterEndParallelItem(ArchiveHandle *AH, TocEntry *te, const char *str, T_Actio
 
 	if (act == ACT_DUMP)
 	{
-		sscanf(str, "%u%n", &dumpId, &nBytes);
+		sscanf(str, "%d%n", &dumpId, &nBytes);
 
 		Assert(dumpId == te->dumpId);
 		Assert(nBytes == strlen(str));
 	}
 	else if (act == ACT_RESTORE)
 	{
-		sscanf(str, "%u %u %u%n", &dumpId, &status, &n_errors, &nBytes);
+		sscanf(str, "%d %d %d%n", &dumpId, &status, &n_errors, &nBytes);
 
 		Assert(dumpId == te->dumpId);
 		Assert(nBytes == strlen(str));