flash_fp_mcu: print canonical path
flash_fp_mcu: print canonical path

This avoids confusion when installing in /usr/local/bin vs /usr/bin.

See https://crbug.com/341708 for more details.

BRANCH=none
BUG=chromium:952447
TEST=emerge-nocturne ec-utils-test && cros deploy nocturne ec-utils-test
     flash_fp_mcu /opt/google/biod/fw/nocturne_fp_v2.2.110-b936c0a3c.bin

Change-Id: Ifba5c668613bc35e24d9466c6e7245b6b862fc90
Signed-off-by: Tom Hughes <fc5c12f30a5ed2baa0581f44ee14ad1eb7b20d83@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1566650
Commit-Ready: ChromeOS CL Exonerator Bot <fa429e5907f00867f797423aea74327bb02c91b6@appspot.gserviceaccount.com>
Reviewed-by: Nicolas Norvez <3001a977f47a2bc94ec05551872e2ce88b323556@chromium.org>

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