btrfs-progs: add -V description in print_usage

mkfs supports the option -V/--version.
Add its description to print_usage().

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/mkfs.c b/mkfs.c
index 8fda48a8..7b72926a 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -350,6 +350,7 @@ static void print_usage(void)
 	fprintf(stderr, "\t -s --sectorsize min block allocation\n");
 	fprintf(stderr, "\t -r --rootdir the source directory\n");
 	fprintf(stderr, "\t -K --nodiscard do not perform whole device TRIM\n");
+	fprintf(stderr, "\t -V --version print the mkfs.btrfs version and exit\n");
 	fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);
 	exit(1);
 }