dut-console: add the missing quotation mark

Add the missing quotation mark in help message.

The help message was:
${CROSS_ARCH}-gdb \
        /build/${BOARD}/usr/lib/debug/boot/vmlinux \
        -ex "target remote $(cat /tmp/kdmx_cpu_9001_gdb)
                                                        ^
                                               not closed

BUG=None
TEST=dut-console -c cpu -p 9001 -k

Change-Id: Idfa55858cb4914fe832d4f7f9d78ef9d14297c01
Signed-off-by: Tzung-Bi Shih <tzungbi@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1725378
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
1 file changed