grep: properly handle grep -w "^str" in !EXTRA_COMPAT case too

function                                             old     new   delta
grep_file                                           1267    1288     +21

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
udhcpc: in comments, explain the kind of raw socket we create

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>