r300: Initialize compiler.max_temp_regs for blits.

Blits were broken since commit e41a64591b
('r300/compiler: make the max number of fragment shader temporaries
adjustable').

src/mesa/drivers/dri/r300/r300_blit.c

@@ -118,6 +118,7 @@ static void create_fragment_program(struct r300_context *r300)
     compiler.OutputColor[0] = FRAG_RESULT_COLOR;
     compiler.OutputDepth = FRAG_RESULT_DEPTH;
     compiler.is_r500 = (r300->radeon.radeonScreen->chip_family >= CHIP_FAMILY_RV515);
+    compiler.max_temp_regs = (compiler.is_r500) ? 128 : 32;
     compiler.code = &r300->blit.fp_code;
     compiler.AllocateHwInputs = fp_allocate_hw_inputs;