GCC4.6: Squash warning in lzo1x_decompress.c

lzo1x_decompress.c: In function ‘parse_header’:
lzo1x_decompress.c:35:5: warning: variable ‘level’ set but not used
[-Wunused-but-set-variable]

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>