upload-archive: do not copy repo name

According to the comment, enter_repo will modify its input.
However, this has not been the case since 1c64b48
(enter_repo: do not modify input, 2011-10-04). Drop the
now-useless copy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/upload-archive.c b/builtin/upload-archive.c
index b928beb..c3d134e 100644
--- a/builtin/upload-archive.c
+++ b/builtin/upload-archive.c
@@ -27,13 +27,8 @@
 	if (argc != 2)
 		usage(upload_archive_usage);
 
-	if (strlen(argv[1]) + 1 > sizeof(buf))
-		die("insanely long repository name");
-
-	strcpy(buf, argv[1]); /* enter-repo smudges its argument */
-
-	if (!enter_repo(buf, 0))
-		die("'%s' does not appear to be a git repository", buf);
+	if (!enter_repo(argv[1], 0))
+		die("'%s' does not appear to be a git repository", argv[1]);
 
 	/* put received options in sent_argv[] */
 	sent_argc = 1;