usr.sbin/ndp: small fixes

[garga]

Summary

usr.sbin/ndp:

• Constify rtpref_str declaration
• Remove unused h_errno declaration
• Use time_t type for expire
• Use strlcpy to set static "?" value to ifname
• Rename local variable 's' to stop shadowing global definition
• Close socket used in pfx_flush()
• Use local variables for sock() in setdefif() and getdefif()
• Increase WARNS to 3

[kevans]

usr.sbin/ndp/ndp.c

670 ↗

(On Diff #29388)

You might as well change this to ifname == NULL while you're touching the area, since ifname is actually a pointer.

671 ↗

(On Diff #29388)

ifname is actually NULL here, so the strlcpy dest and size should be of ifix_buf (and set ifname = ifix_buf)

[garga]

Address @kevans comments

[garga]

Fixed reversed check

[allanjude]

Approved By: allanjude