Fix non-PIC build after 253959
Fix non-PIC build after 253959

CMAKE_EXE_LINKER_FLAGS is a string. Appending a flag using list(APPEND) introduces an extra
semicolon which breaks stuff. Change this to append the value in the same way that everyone else
seems to be doing.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@253968 91177308-0d34-0410-b5e6-96231b3b80d8

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