busybox: 1.20.0 buildsys fix

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/busybox/busybox-1.20.0/busybox-1.20.0-buildsys.patch

@@ -0,0 +1,11 @@
+--- busybox-1.20.0/archival/libarchive/Kbuild.src
++++ busybox-1.20.0-buildsys/archival/libarchive/Kbuild.src
+@@ -60,7 +60,7 @@ lib-$(CONFIG_FEATURE_SEAMLESS_GZ)
+ lib-$(CONFIG_FEATURE_SEAMLESS_BZ2)      += open_transformer.o decompress_bunzip2.o
+ lib-$(CONFIG_FEATURE_SEAMLESS_LZMA)     += open_transformer.o decompress_unlzma.o
+ lib-$(CONFIG_FEATURE_SEAMLESS_XZ)       += open_transformer.o decompress_unxz.o
+-lib-$(CONFIG_FEATURE_COMPRESS_USAGE)    += decompress_bunzip2.o
++lib-$(CONFIG_FEATURE_COMPRESS_USAGE)    += open_transformer.o decompress_bunzip2.o
+ lib-$(CONFIG_FEATURE_COMPRESS_BBCONFIG) += decompress_bunzip2.o
+ lib-$(CONFIG_FEATURE_TAR_TO_COMMAND)    += data_extract_to_command.o
+