Silence an unused variable warning on release builds.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159074 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
index 79af9a7..d175e3e 100644
--- a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+++ b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
@@ -104,9 +104,9 @@
 
     // Print the CR bit number. The Code is ((BI << 5) | BO) for a
     // BCC, but we must have the positive form here (BO == 12)
-    unsigned BO = Code & 0xF;
     unsigned BI = Code >> 5;
-    assert(BO == 12 && "BO in predicate bit must have the positive form");
+    assert((Code & 0xF) == 12 &&
+           "BO in predicate bit must have the positive form");
 
     unsigned Value = 4*RegNo + BI;
     O << Value;