winsys/amdgpu: consolidate IB size management in amdgpu_ib_finalize
winsys/amdgpu: consolidate IB size management in amdgpu_ib_finalize

Reviewed-by: Marek Olšák <8c7344a1abdb103e79ecfd488098373070c3c70e@amd.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler