[OpenCL] Revert urMemBufferCreate extension function lookup error

This commit reverts the urMemBufferCreate changes for returning function
lookup error in #1448
as the function had a fallback path which is no longer taken.

Signed-off-by: Larsen, Steffen <steffen.larsen@intel.com>

source/adapters/opencl/memory.cpp

@@ -232,11 +232,11 @@ UR_APIEXPORT ur_result_t UR_APICALL urMemBufferCreate(
  clCreateBufferWithPropertiesINTEL_fn FuncPtr = nullptr;
  cl_context CLContext = cl_adapter::cast<cl_context>(hContext);
  // First we need to look up the function pointer
- UR_RETURN_ON_FAILURE(
+ RetErr =
  cl_ext::getExtFuncFromContext<clCreateBufferWithPropertiesINTEL_fn>(
  CLContext,
  cl_ext::ExtFuncPtrCache->clCreateBufferWithPropertiesINTELCache,
- cl_ext::CreateBufferWithPropertiesName, &FuncPtr));
+ cl_ext::CreateBufferWithPropertiesName, &FuncPtr);
  if (FuncPtr) {
  std::vector<cl_mem_properties_intel> PropertiesIntel;
  auto Prop = static_cast<ur_base_properties_t *>(pProperties->pNext);