clEnqueueFillImage: handle 1D image buffers correctly
clEnqueueFillImage: handle 1D image buffers correctly

the previous code was creating pocl_command with the image, not the buffer.

Oblomov/pocl,rjodin/pocl,pocl/pocl,pocl/pocl,rjodin/pocl,rjodin/pocl,Oblomov/pocl,franz/pocl,Oblomov/pocl,franz/pocl,rjodin/pocl,franz/pocl,pocl/pocl,Oblomov/pocl,pocl/pocl,franz/pocl,franz/pocl,Oblomov/pocl,pocl/pocl