CmbIpc: Fix wrong block size
CmbIpc: Fix wrong block size

The block size was one to big and so the command could only read after a
new command arrived.

Change-Id: I64ae47667d27d66e132031b10d4f130c53d3b0e9
Reviewed-by: Nikolai Kosjar <9571db158ca61a0d070db010803474231fa0cbab@theqtcompany.com>

xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator