Making discarded-qualifiers a gcc error instead of warning?

[Tom Yu]

Will Fiveash <will.fiveash at oracle.com> writes:

> ../../../../krb5-1.14.3/src/lib/krb5/krb/chpw.c: In function 'krb5int_mk_chpw_req':
> ../../../../krb5-1.14.3/src/lib/krb5/krb/chpw.c:32:18: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>      clearpw.data = passwd;
>                   ^
> ../../../../krb5-1.14.3/src/lib/krb5/krb/chpw.c: In function 'krb5int_mk_setpw_req':
> ../../../../krb5-1.14.3/src/lib/krb5/krb/chpw.c:305:23: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>      req.password.data = passwd;
>                        ^
> ../../../../../krb5-1.14.3/src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c: In function 'has_rootdse_ava':
> ../../../../../krb5-1.14.3/src/plugins/kdb/ldap/libkdb_ldap/kdb_ldap.c:135:14: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
>      attrs[0] = attribute;
>               ^

I think e534f688db29945e4efde425f62ce7dae4608f6f (on master) already
fixed the chpw.c cases, and 66acc3b529f997f902bf11d3004ddc065d5bea9f
(also on master) fixed the kdb_ldap.c case.  They're not currently
marked for pullup to release branches, but I'm willing to consider doing
so if they're not too difficult to back port.

-Tom