GBE: fixed a prediction bug in typed write instruction.

GBE: fixed a prediction bug in typed write instruction.

We need to put the header initialization and the LOD initialization
to no mask and no predication state. For all the other parts, we need
to enable mask and use the current predication state and need to set
the quater control properly. Otherwise, when write_image is called in
a condition-branch block, it will trigger this bug and doesn't write
data out correctly.

Signed-off-by: Zhigang Gong <zhigang.gong@linux.intel.com>
Tested-by: Lv, Meng <meng.lv@intel.com>