WebAssembly: NFC fix release build break, unused variable.
WebAssembly: NFC fix release build break, unused variable.

Summary: Caused by D11914, pointed out by blaikie.

Subscribers: llvm-commits, jfb, dblaikie

Differential Revision: http://reviews.llvm.org/D11929

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@244570 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm