mkXXXX: unify [KBYTES] parameter handling (added it to mkswap)

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/Kbuild b/libbb/Kbuild
index 7e79310..c205ceb 100644
--- a/libbb/Kbuild
+++ b/libbb/Kbuild
@@ -42,6 +42,7 @@
 lib-y += get_line_from_file.o
 lib-y += getopt32.o
 lib-y += getpty.o
+lib-y += get_volsize.o
 lib-y += herror_msg.o
 lib-y += herror_msg_and_die.o
 lib-y += human_readable.o