[SYCL] Fix UNSUPPORTED syntax for DiscardEvents/invalid_event.cpp (#665)

As shown by CI for #569, the unsupported combination of opencl && acc
still shows up. Attempt to fix this by using a common operator style
as a follow-up to #652.

Signed-off-by: Artem Gindinson <[email protected]>

Author: Artem Gindinson

SYCL/DiscardEvents/invalid_event.cpp

@@ -1,5 +1,5 @@
 // FIXME: fails on HIP and accelerator
-// UNSUPPORTED: hip, (opencl && acc)
+// UNSUPPORTED: hip || (opencl && acc)
 // RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
 //
 // RUN: %HOST_RUN_PLACEHOLDER %t.out