spirv-val: Improve PR 4831 error message (#4968)

source/val/validate_decorations.cpp

diff --git a/source/val/validate_decorations.cpp b/source/val/validate_decorations.cpp
index 81c9094..c4834cd 100644
--- a/source/val/validate_decorations.cpp
+++ b/source/val/validate_decorations.cpp
@@ -853,17 +853,18 @@
                   (models->size() > 1 || has_vert)) {
                 return vstate.diag(SPV_ERROR_INVALID_ID, var_instr)
                        << vstate.VkErrorID(6202)
-                       << "OpEntryPoint interfaces variable must not be vertex "
-                          "execution model with an input storage class for "
-                          "Entry Point id "
+                       << vstate.SpvDecorationString(decoration.dec_type())
+                       << " decorated variable must not be used in vertex "
+                          "execution model as an Input storage class for Entry "
+                          "Point id "
                        << entry_point << ".";
               } else if (storage_class == SpvStorageClassOutput &&
                          (models->size() > 1 || has_frag)) {
                 return vstate.diag(SPV_ERROR_INVALID_ID, var_instr)
                        << vstate.VkErrorID(6201)
-                       << "OpEntryPoint interfaces variable must not be "
-                          "fragment "
-                          "execution model with an output storage class for "
+                       << vstate.SpvDecorationString(decoration.dec_type())
+                       << " decorated variable must not be used in fragment "
+                          "execution model as an Output storage class for "
                           "Entry Point id "
                        << entry_point << ".";
               }

test/val/val_decoration_test.cpp

diff --git a/test/val/val_decoration_test.cpp b/test/val/val_decoration_test.cpp
index 0762670..d895873 100644
--- a/test/val/val_decoration_test.cpp
+++ b/test/val/val_decoration_test.cpp
@@ -8756,9 +8756,8 @@
               AnyVUID("VUID-StandaloneSpirv-Flat-06201"));
   EXPECT_THAT(
       getDiagnosticString(),
-      HasSubstr(
-          "OpEntryPoint interfaces variable must not be fragment execution "
-          "model with an output storage class for Entry Point id 2."));
+      HasSubstr("decorated variable must not be used in fragment execution "
+                "model as an Output storage class for Entry Point id 2."));
 }
 
 TEST_P(ValidateDecorationString, VulkanVertexInputInvalidInterface) {
@@ -8796,8 +8795,8 @@
               AnyVUID("VUID-StandaloneSpirv-Flat-06202"));
   EXPECT_THAT(
       getDiagnosticString(),
-      HasSubstr("OpEntryPoint interfaces variable must not be vertex execution "
-                "model with an input storage class for Entry Point id 2."));
+      HasSubstr("decorated variable must not be used in vertex execution model "
+                "as an Input storage class for Entry Point id 2."));
 }
 
 INSTANTIATE_TEST_SUITE_P(FragmentInputInterface, ValidateDecorationString,