env: fix endian ordering in crc table

The crc table was being built as little endian for big endian
targets.  This would cause fw_printenv to always fail with
"Warning: Bad CRC, using default environment" messages.

Signed-off-by: Jeff Angielski <jeff@theptrgroup.com>
Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
diff --git a/lib_generic/crc32.c b/lib_generic/crc32.c
index 468b397..27335a3 100644
--- a/lib_generic/crc32.c
+++ b/lib_generic/crc32.c
@@ -163,7 +163,7 @@
 #endif
 
 /* ========================================================================= */
-# ifdef __LITTLE_ENDIAN
+# if __BYTE_ORDER == __LITTLE_ENDIAN
 #  define DO_CRC(x) crc = tab[(crc ^ (x)) & 255] ^ (crc >> 8)
 # else
 #  define DO_CRC(x) crc = tab[((crc >> 24) ^ (x)) & 255] ^ (crc << 8)