*: remove a few more cases of argc usage. -89 bytes.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/Kbuild b/libbb/Kbuild
index d9d5ad7..130ad25 100644
--- a/libbb/Kbuild
+++ b/libbb/Kbuild
@@ -92,6 +92,7 @@
 lib-y += sha1.o
 lib-y += signals.o
 lib-y += simplify_path.o
+lib-y += single_argv.o
 lib-y += skip_whitespace.o
 lib-y += speed_table.o
 lib-y += str_tolower.o