[NFC] OSSACompleteLifetime: Tweak control flow.

Use a switch rather than several ifs.

Author: nate-chandler

include/swift/SIL/OSSALifetimeCompletion.h

@@ -93,17 +93,24 @@ class OSSALifetimeCompletion {
   ///
   /// TODO: We also need to complete scoped addresses (e.g. store_borrow)!
   LifetimeCompletion completeOSSALifetime(SILValue value, Boundary boundary) {
-    if (value->getOwnershipKind() == OwnershipKind::None)
+    switch (value->getOwnershipKind()) {
+    case OwnershipKind::None:
       return LifetimeCompletion::NoLifetime;
-
-    if (value->getOwnershipKind() != OwnershipKind::Owned) {
+    case OwnershipKind::Owned:
+      break;
+    case OwnershipKind::Any:
+      llvm::report_fatal_error("value with any ownership kind!?");
+    case OwnershipKind::Guaranteed:
+    case OwnershipKind::Unowned: {
       BorrowedValue borrowedValue(value);
       if (!borrowedValue)
         return LifetimeCompletion::NoLifetime;
 
       if (!borrowedValue.isLocalScope())
         return LifetimeCompletion::AlreadyComplete;
     }
+    }
+
     if (!completedValues.insert(value))
       return LifetimeCompletion::AlreadyComplete;