net-libs/libsmi: build w/ -std=gnu17

Brittle enough.

Closes: https://bugs.gentoo.org/944131
Signed-off-by: Sam James <sam@gentoo.org>

net-libs/libsmi/libsmi-0.5.0-r5.ebuild

@@ -3,7 +3,7 @@
 
 EAPI=8
 
-inherit autotools
+inherit autotools flag-o-matic
 
 DESCRIPTION="A Library to Access SMI MIB Information"
 HOMEPAGE="https://www.ibr.cs.tu-bs.de/projects/libsmi/ https://gitlab.ibr.cs.tu-bs.de/nm/libsmi"
@@ -31,6 +31,13 @@ src_prepare() {
 	eautoreconf
 }
 
+src_configure() {
+	# bug #944131
+	append-cflags -std=gnu17
+
+	econf
+}
+
 src_test() {
 	# sming test is known to fail and some other fail if LC_ALL!=C:
 	# https://mail.ibr.cs.tu-bs.de/pipermail/libsmi/2008-March/001014.html