[NFC] Wrap entire assert-only block in LLVM_DEBUG

Author: rupprecht

llvm/lib/Target/AMDGPU/SIOptimizeVGPRLiveRange.cpp

@@ -161,10 +161,12 @@ void SIOptimizeVGPRLiveRange::collectElseRegionBlocks(
       MBB = nullptr;
   }
 
-  LLVM_DEBUG(dbgs() << "Found Else blocks: ");
-  for (auto *MBB : Blocks)
-    LLVM_DEBUG(dbgs() << printMBBReference(*MBB) << ' ');
-  LLVM_DEBUG(dbgs() << '\n');
+  LLVM_DEBUG({
+    dbgs() << "Found Else blocks: ";
+    for (auto *MBB : Blocks)
+      dbgs() << printMBBReference(*MBB) << ' ';
+    dbgs() << '\n';
+  });
 }
 
 /// Find the instructions(excluding phi) in \p MBB that uses the \p Reg.