ip route: check ftell, fseek return value

ftell() may return -1 in error case, which is not handled and
therefore pass a negative offset to fseek(). The return code of
fseek() is also not checked.

Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
1 file changed