[mtools] Two things about file open mode

[Eugene Kotlyarov]

Hello

  1. filemode for -C option of mformat should probably include O_TRUNC 
option or it can create images with wrong size
  2. Maybe it would be better to explicitly open image files in binary 
mode. Now it causes problems in certain configuration on Cygwin
--- mformat.orig.c      2004-05-04 10:15:55.140625000 +0400
+++ mformat.c   2004-05-04 10:16:20.250000000 +0400
@@ -874,7 +874,7 @@
                                break;
 
                        case 'C':
-                               create = O_CREAT;
+                               create = O_CREAT | O_TRUNC;
                                break;
 
                        case 'H':

--- plain_io.orig.c     2004-05-04 10:17:17.906250000 +0400
+++ plain_io.c  2004-05-04 10:17:35.656250000 +0400
@@ -599,7 +599,7 @@
                    This->fd = scsi_open(name, mode, IS_NOLOCK(dev)?0444:0666,
                                         &This->extra_data);
                else
-                   This->fd = open(name, mode | O_LARGEFILE, 
+                   This->fd = open(name, mode | O_LARGEFILE | O_BINARY, 
                                    IS_NOLOCK(dev)?0444:0666);
            }