hardening: remove the empty line before EOF

The extra empty line broke the "ninja hardenconfig" on my machine with
Python 3.7.5, it complains:

"
... ...
File "/home/zephyrproject/zephyr/scripts/kconfig/hardenconfig.py",
line 46, in compare_with_hardened_conf

name = row[0]
IndexError: list index out of range
FAILED: CMakeFiles/hardenconfig
"

The csv.reader reads this empty line and gets an empty list which will
not be successfully "de-referenced".  Removing it to improve the
out-of-box experience when pepople try out the hardening options.

Signed-off-by: Wenbo Yang <wenbo.yangcn@gmail.com>
1 file changed