agx: Don't leak ssa_to_reg_out

calloc'd in the RA, should be freed in the RA. Identified with valgrind.

Fixes: 6b13616cba2 ("agx: Implement vector live range splitting")
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23998>

src/asahi/compiler/agx_register_allocate.c

@@ -1192,6 +1192,11 @@ agx_ra(agx_context *ctx)
       }
    }
 
+   agx_foreach_block(ctx, block) {
+      free(block->ssa_to_reg_out);
+      block->ssa_to_reg_out = NULL;
+   }
+
    free(src_to_collect);
    free(ssa_to_reg);
    free(ncomps);