radeonsi: initialize TC_L2_dirty to false after buffer allocation
radeonsi: initialize TC_L2_dirty to false after buffer allocation

I forgot to do this, though "true" should have no effect on correctness.

Reviewed-by: Michel Dänzer <242b79f0804cf52679d58f27ed754158c1323c75@amd.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler