Fix image access in link-attribute test (#2598)

The test performed a read_image operation on an image declared
`write_only`.  `spirv-val` recently started flagging this.

Update the image access attribute to "read-only" (i.e., 0).

Fixes KhronosGroup/SPIRV-LLVM-Translator#2597

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@bd0fffe337d27b3

Author: svenvh

llvm-spirv/test/link-attribute.ll

@@ -13,19 +13,19 @@ target triple = "spir64-unknown-unknown"
 @imageSampler = addrspace(2) constant i32 36, align 4
 
 ; Function Attrs: nounwind
-define spir_kernel void @sample_kernel(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 1) %input, ptr addrspace(1) nocapture %xOffsets, ptr addrspace(1) nocapture %yOffsets, ptr addrspace(1) nocapture %results) #0 !kernel_arg_addr_space !1 !kernel_arg_access_qual !2 !kernel_arg_type !3 !kernel_arg_base_type !5 !kernel_arg_type_qual !4 {
+define spir_kernel void @sample_kernel(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 0) %input, ptr addrspace(1) nocapture %xOffsets, ptr addrspace(1) nocapture %yOffsets, ptr addrspace(1) nocapture %results) #0 !kernel_arg_addr_space !1 !kernel_arg_access_qual !2 !kernel_arg_type !3 !kernel_arg_base_type !5 !kernel_arg_type_qual !4 {
   %1 = tail call spir_func i64 @_Z13get_global_idj(i32 0) #1
   %2 = trunc i64 %1 to i32
   %3 = tail call spir_func i64 @_Z13get_global_idj(i32 1) #1
   %4 = trunc i64 %3 to i32
-  %5 = tail call spir_func i32 @_Z15get_image_width11ocl_image2d(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 1) %input) #1
+  %5 = tail call spir_func i32 @_Z15get_image_width11ocl_image2d(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 0) %input) #1
   %6 = mul nsw i32 %4, %5
   %7 = add nsw i32 %6, %2
   %8 = sitofp i32 %2 to float
   %9 = insertelement <2 x float> undef, float %8, i32 0
   %10 = sitofp i32 %4 to float
   %11 = insertelement <2 x float> %9, float %10, i32 1
-  %12 = tail call spir_func <4 x float> @_Z11read_imagef11ocl_image2d11ocl_samplerDv2_f(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 1) %input, i32 36, <2 x float> %11) #1
+  %12 = tail call spir_func <4 x float> @_Z11read_imagef11ocl_image2d11ocl_samplerDv2_f(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 0) %input, i32 36, <2 x float> %11) #1
   %13 = sext i32 %7 to i64
   %14 = getelementptr inbounds <4 x float>, ptr addrspace(1) %results, i64 %13
   store <4 x float> %12, ptr addrspace(1) %14, align 16, !tbaa !11
@@ -36,10 +36,10 @@ define spir_kernel void @sample_kernel(target("spirv.Image", void, 1, 0, 0, 0, 0
 declare spir_func i64 @_Z13get_global_idj(i32) #1
 
 ; Function Attrs: nounwind readnone
-declare spir_func i32 @_Z15get_image_width11ocl_image2d(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 1)) #1
+declare spir_func i32 @_Z15get_image_width11ocl_image2d(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 0)) #1
 
 ; Function Attrs: nounwind readnone
-declare spir_func <4 x float> @_Z11read_imagef11ocl_image2d11ocl_samplerDv2_f(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 1), i32, <2 x float>) #1
+declare spir_func <4 x float> @_Z11read_imagef11ocl_image2d11ocl_samplerDv2_f(target("spirv.Image", void, 1, 0, 0, 0, 0, 0, 0), i32, <2 x float>) #1
 
 attributes #0 = { nounwind }
 attributes #1 = { nounwind readnone }