[NFC][SYCL] Removed test case which is clearly prohibited by compiler

Author: vladimirlaz

clang/test/SemaSYCL/loop_unroll.cpp

@@ -32,11 +32,6 @@ void foo() {
   [[clang::loop_unroll(4)]]
   for (int i = 0; i < 10; ++i);
 
-  // expected-error@+2 {{incompatible loop unroll instructions: '#pragma unroll(4)' and '[[clang::loop_unroll(2)]]'}}
-#pragma unroll 4
-  [[clang::loop_unroll(2)]]
-  for (int i = 0; i < 10; ++i);
-
   // no error expected
   [[clang::loop_unroll(4)]]
   [[intelfpga::ii(2)]]