Smatch reports for zynqmp video driver

[Andrew Goodbody]

Smatch reports the following two issues

drivers/video/zynqmp/zynqmp_dpsub.c:271 config_gfx_pipeline() error: 
uninitialized symbol 'offset_matrix'.
drivers/video/zynqmp/zynqmp_dpsub.c:277 config_gfx_pipeline() error: 
uninitialized symbol 'csc_matrix'.

Looking at the code, offset_matrix and csc_matrix are only initialised 
if video->is_rgb is true. It looks almost as if the code for 
video->is_rgb being false was never written. So I am not sure of the 
correct fix for this.

Andrew