tar: add -o and -k to short --help too

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/tar.c b/archival/tar.c
index 4515d42..224cb47 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -759,7 +759,7 @@
 //usage:	IF_FEATURE_SEAMLESS_LZMA("a")
 //usage:	IF_FEATURE_TAR_CREATE("h")
 //usage:	IF_FEATURE_TAR_NOPRESERVE_TIME("m")
-//usage:	"vO] "
+//usage:	"vokO] "
 //usage:	"[-f TARFILE] [-C DIR] "
 //usage:	IF_FEATURE_TAR_FROM("[-T FILE] [-X FILE] "IF_FEATURE_TAR_LONG_OPTIONS("[--exclude PATTERN]... "))
 //usage:	"[FILE]..."
@@ -776,6 +776,10 @@
 //usage:     "\n	-f FILE	Name of TARFILE ('-' for stdin/out)"
 //usage:     "\n	-C DIR	Change to DIR before operation"
 //usage:     "\n	-v	Verbose"
+//usage:     "\n	-O	Extract to stdout"
+//usage:	IF_FEATURE_TAR_NOPRESERVE_TIME(
+//usage:     "\n	-m	Don't restore mtime"
+//usage:	)
 //usage:     "\n	-o	Don't restore user:group"
 ///////:-p - accepted but ignored, restores mode (aliases in GNU tar: --preserve-permissions, --same-permissions)
 //usage:     "\n	-k	Don't replace existing files"
@@ -794,13 +798,9 @@
 //usage:	IF_FEATURE_SEAMLESS_LZMA(
 //usage:     "\n	-a	(De)compress using lzma"
 //usage:	)
-//usage:     "\n	-O	Extract to stdout"
 //usage:	IF_FEATURE_TAR_CREATE(
 //usage:     "\n	-h	Follow symlinks"
 //usage:	)
-//usage:	IF_FEATURE_TAR_NOPRESERVE_TIME(
-//usage:     "\n	-m	Don't restore mtime"
-//usage:	)
 //usage:	IF_FEATURE_TAR_FROM(
 //usage:     "\n	-T FILE	File with names to include"
 //usage:     "\n	-X FILE	File with glob patterns to exclude"