nv30: create uploader after pipe->screen is set
nv30: create uploader after pipe->screen is set

Fixes crashes after recent upload rework.

Signed-off-by: Ilia Mirkin <bcbbb7aa705ec3a5fc5824c01a845186c3d62fca@alum.mit.edu>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler