clang: Rename misleading test name

This is a test for attribute propagation, not metadata

diff --git a/clang/test/CodeGenCUDA/propagate-metadata.cu b/clang/test/CodeGenCUDA/propagate-attributes.cu
similarity index 100%
rename from clang/test/CodeGenCUDA/propagate-metadata.cu
rename to clang/test/CodeGenCUDA/propagate-attributes.cu