util: uartupdatetool: do not strip trailing white space
util: uartupdatetool: do not strip trailing white space

uartupdatetool won't ignore trailing white space.
It will erase flash segments for sure corresponding to that part.

BUG=b:139884342
BRANCH=None
TEST=manually ran flash_ec on hatch through ccd with two different
binaries: one ${IMG1} has less trailing 0xFF space than the other
${IMG2}.

flash_ec --board hatch --image ${IMG1} --verify
flash_ec --board hatch --image ${IMG2} --verify

Change-Id: Id25a9e05a2d2df76255dd688f829dee48dc819cf
Signed-off-by: Namyoon Woo <e8732cefb861f07768f47df788a8e8eb75efc09a@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1766099
Reviewed-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec