ZTS: increase timeout of mmap_sync_001_pos

On load the test needs sometimes a bit more time then just one second.
Doubling the time will help on the QEMU based testings.

Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Tino Reichardt <milky-zfs@mcmilk.de>
Closes openzfs#16537

tests/zfs-tests/cmd/mmap_sync.c

@@ -64,7 +64,7 @@ main(int argc, char *argv[])
 		run_time_mins = atoi(argv[1]);
 	}
 
-	int max_msync_time_ms = 1000;
+	int max_msync_time_ms = 2000;
 	if (argc >= 3) {
 		max_msync_time_ms = atoi(argv[2]);
 	}