configure: Remove unused code (found by shellcheck)

smartcard_cflags is no longer needed since commit
0b22ef0f57a8910d849602bef0940edcd0553d2c.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
1 file changed