net: ipv4: Fix the warning for dereference
Add a if statements to avoid the warning.
Dan Carpenter report:
The patch
faf482ca196a: "net: ipv4: Move ip_options_fragment() out of
loop" from Aug 23, 2021, leads to the following Smatch complaint:
net/ipv4/ip_output.c:833 ip_do_fragment()
warn: variable dereferenced before check 'iter.frag' (see line 828)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes:
faf482ca196a ("net: ipv4: Move ip_options_fragment() out of loop")
Link: https://lore.kernel.org/netdev/20210830073802.GR7722@kadam/T/#t
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>