Remove unnecessary null check.  NFC.

Since both places which set this variable do so with dyn_cast, and not
dyn_cast_or_null, its impossible to get a nullptr here, so we can remove
the check.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243167 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed