mtd: cfi: cmdset_0002: remove redundant variable timeo

Variable is_local is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'timeo' set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>