Removed unused variable

Change-Id: I9236d02e04fb58a081c608d16f4e1eadf81dde16
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/26949Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>