archival/*: move "applet:" snippets into .c files

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/tar.c b/archival/tar.c
index f75a82a..2504258 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -42,6 +42,7 @@
  * This doesn't feel right, and IIRC GNU tar doesn't do that.
  */
 
+//applet:IF_TAR(APPLET(tar, BB_DIR_BIN, BB_SUID_DROP))
 //kbuild:lib-$(CONFIG_TAR) += tar.o
 
 #include <fnmatch.h>