layers: Clarify MaxAnisotropy not enabled message

Folks continue to confuse 'enabled' with 'supported', expecially on
this particular feature.

Change-Id: I73df704436a95c9c47194169a53602b87b422174
diff --git a/layers/parameter_validation.cpp b/layers/parameter_validation.cpp
index e081e54..c933a59 100644
--- a/layers/parameter_validation.cpp
+++ b/layers/parameter_validation.cpp
@@ -2456,12 +2456,11 @@
     skip |= parameter_validation_vkCreateSampler(device_data, pCreateInfo, pAllocator, pSampler);
 
     if (pCreateInfo != nullptr) {
-
         if ((device_data->physical_device_features.samplerAnisotropy == false) && (pCreateInfo->maxAnisotropy != 1.0)) {
             skip |= log_msg(report_data, VK_DEBUG_REPORT_ERROR_BIT_EXT, VK_DEBUG_REPORT_OBJECT_TYPE_UNKNOWN_EXT, 0, __LINE__,
                             DEVICE_FEATURE, LayerName,
-                            "vkCreateSampler(): The samplerAnisotropy feature is not enabled, so the maxAnisotropy member of the "
-                            "VkSamplerCreateInfo structure must be 1.0 but is %f.",
+                            "vkCreateSampler(): The samplerAnisotropy feature was not enabled at device-creation time, so the "
+                            "maxAnisotropy member of the VkSamplerCreateInfo structure must be 1.0 but is %f.",
                             pCreateInfo->maxAnisotropy);
         }