use abstract interface

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100758 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index 45e14bf..0d0af46 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -274,7 +274,7 @@
     
     // isInlineAsm - Check if the instruction is a call to an inline asm chunk
     static bool isInlineAsm(const Instruction& I) {
-      if (isa<CallInst>(&I) && isa<InlineAsm>(I.getOperand(0)))
+      if (isa<CallInst>(&I) && isa<InlineAsm>(I.getCalledValue()))
         return true;
       return false;
     }