[test][llvm-dwarfdump] Remove pointless CHECK-NOT lines
[test][llvm-dwarfdump] Remove pointless CHECK-NOT lines

The original line was there from when this test was added, but it is
checking for a switch that doesn't exist, so really has no purpose, at
least any more.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@363833 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm