uboot-imx

tpm: simplify: tpm_set_global_lock()

When in pack_byte_string() memcpy() is called for size 0 the source buffer
address has no relevance. So we can use NULL here.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>