src/netlink.c: remove REG_NOERROR

src/netlink.c: remove REG_NOERROR

REG_NOERROR is used since version 5.12.0 and
https://github.com/collectd/collectd/commit/f7fd32e5209e188db7985a42054252fc4cbfe7c1

However, REG_NOERROR is not defined by musl, even GNU regex do not
mention REG_NOERROR, so just remove it to avoid the following build
failure:

src/netlink.c: In function 'check_ignorelist':
src/netlink.c:243:51: error: 'REG_NOERROR' undeclared (first use in this function); did you mean 'REG_NOTBOL'?
       if (regexec(i->rdevice, dev, 0, NULL, 0) != REG_NOERROR)
                                                   ^~~~~~~~~~~
                                                   REG_NOTBOL

Fixes:
 - http://autobuild.buildroot.org/results/cd4d75888b5259b028132dd224be34f69bcbb702

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>