github-upload-release.py: Fix bug preventing release creation (llvm#84571)

After aa02002 we started passing the
user name to the create_release function and this was being interpreted
as the git tag.

(cherry picked from commit 0b9ce71)

Author: tstellar

llvm/utils/release/github-upload-release.py

@@ -107,6 +107,6 @@ def upload_files(repo, release, files):
     sys.exit(1)
 
 if args.command == "create":
-    create_release(llvm_repo, args.release, args.user)
+    create_release(llvm_repo, args.release)
 if args.command == "upload":
     upload_files(llvm_repo, args.release, args.files)