tar: fix fallout of: change -a from meaning "lzma" to mean "autodetect by extension"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/tar.c b/archival/tar.c
index 4f64d22..4ab38db 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -1029,7 +1029,7 @@
 		IF_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
 		IF_NOT_FEATURE_TAR_CREATE("t--x:x--t") // mutually exclusive
 #if ENABLE_FEATURE_TAR_LONG_OPTIONS
-		":\xf9+" // --strip-components=NUM
+		":\xf8+" // --strip-components=NUM
 #endif
 		LONGOPTS
 		, &base_dir // -C dir