[AMDGPU] update test to replace undef with poison.

Author: skc7

llvm/test/CodeGen/AMDGPU/amdgpu-sw-lower-lds-static-lds-test-O0.ll

@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals all --version 4
 ; RUN: opt < %s -passes='function(infer-address-spaces),amdgpu-sw-lower-lds' -S  -mtriple=amdgcn-amd-amdhsa | FileCheck %s
-@lds = internal addrspace(3) global [5 x i32] undef, align 16
+@lds = internal addrspace(3) global [5 x i32] poison, align 16
 
 ;.
 ; CHECK: @llvm.amdgcn.sw.lds.k0 = internal addrspace(3) global ptr poison, no_sanitize_address, align 16, !absolute_symbol [[META0:![0-9]+]]