Fix a typo 'iff' => 'if'

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164767 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFastISel.cpp b/lib/Target/ARM/ARMFastISel.cpp
index 8933a02..1458e33 100644
--- a/lib/Target/ARM/ARMFastISel.cpp
+++ b/lib/Target/ARM/ARMFastISel.cpp
@@ -276,7 +276,7 @@
   if (TII.isPredicable(MI) || isARMNEONPred(MI))
     AddDefaultPred(MIB);
 
-  // Do we optionally set a predicate?  Preds is size > 0 iff the predicate
+  // Do we optionally set a predicate?  Preds is size > 0 if the predicate
   // defines CPSR. All other OptionalDefines in ARM are the CCR register.
   bool CPSR = false;
   if (DefinesOptionalPredicate(MI, &CPSR)) {