libbb: commonalize a bit of little-endian CRC32 table generation code

function                                             old     new   delta
global_crc32_new_table_le                              -      11     +11
crc32_new_table_le                                     -       9      +9
inflate_unzip_internal                               560     556      -4
flash_eraseall_main                                  823     819      -4
unpack_xz_stream                                    2403    2394      -9
lzop_main                                            121     112      -9
gzip_main                                            187     178      -9
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/5 up/down: 20/-35)            Total: -15 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/libarchive/decompress_unxz.c b/archival/libarchive/decompress_unxz.c
index 0be8550..8ae7a27 100644
--- a/archival/libarchive/decompress_unxz.c
+++ b/archival/libarchive/decompress_unxz.c
@@ -52,7 +52,7 @@
 	IF_DESKTOP(long long) int total = 0;
 
 	if (!global_crc32_table)
-		global_crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
+		global_crc32_new_table_le();
 
 	memset(&iobuf, 0, sizeof(iobuf));
 	membuf = xmalloc(2 * BUFSIZ);