test: mbr: Adjust test to drop 0x

U-Boot commands typically don't need 0x to specify hex, since they use
hex by default. Adding 0x in this test is confusing since it suggests
that it is necessary. Drop it from the file.

Also use the %#x construct to get the 0x when needed.

Signed-off-by: Simon Glass <sjg@chromium.org>
1 file changed