ac/nir: remove useless integer cast in visit_image_load()

ac_build_image_opcode() casts if necessary and buffer images
are casted too.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/amd/common/ac_nir_to_llvm.c

@@ -2550,7 +2550,7 @@ static LLVMValueRef visit_image_load(struct ac_nir_context *ctx,
 
 		res = ac_build_image_opcode(&ctx->ac, &args);
 	}
-	return ac_to_integer(&ctx->ac, res);
+	return res;
 }
 
 static void visit_image_store(struct ac_nir_context *ctx,