[SYCL][RTC] Fix post-commit failure (#16174)

Fixes post-commit failure due to an unused variable introduced by
#16109.

---------

Signed-off-by: Julian Oppermann <julian.oppermann@codeplay.com>

Author: jopperm

sycl-jit/jit-compiler/lib/rtc/DeviceCompilation.cpp

@@ -402,8 +402,7 @@ Expected<RTCBundleInfo> jit_compiler::performPostLink(
       ModuleDesc{std::unique_ptr<llvm::Module>{&Module}}, SPLIT_NONE,
       /*IROutputOnly=*/false,
       /*EmitOnlyKernelsAsEntryPoints=*/true);
-  bool SplitOccurred = Splitter->remainingSplits() > 1;
-  assert(!SplitOccurred);
+  assert(Splitter->remainingSplits() == 1);
 
   // TODO: Call `verifyNoCrossModuleDeviceGlobalUsage` if device globals shall
   //       be processed.