Signed-off-by: W. Michael Petullo <mike@flyn.org>

This replaces the use of uci_validate_section() with
uci_load_validate(), which removes the need to declare local variables
for every config option.

This also fixes a variable name typo ("CONFIGFILE" instead of
"config_file").

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

Signed-off-by: W. Michael Petullo <mike@flyn.org>

Signed-off-by: Luka Perkov <luka@openwrt.org>