converity: fix Argument cannot be negative in libini
converity: fix Argument cannot be negative in libini

ftell can return -1 on error, and we were not looking
for that before using that with malloc().

Capture the return as a signed number and
check for the negative return value.

Signed-off-by: Robin Getz <c66e5a86ef9317cf35cecb2ed063996b2100ed4b@analog.com>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio