Fix build on GCC architectures

PR:		241894
Submitted by:	pkubaj
MFH:		2019Q4 (blanket)

net-mgmt/driftnet/Makefile

@@ -19,6 +19,7 @@ BUILD_DEPENDS=	makedepend:devel/makedepend
 GNU_CONFIGURE=	yes
 USES=		autoreconf gettext-runtime gmake gnome jpeg localbase:ldflags \
 		pkgconfig xorg
+USE_CSTD=	c99
 USE_GITHUB=	yes
 USE_GNOME=	gtk20
 USE_XORG=	x11 xext xi

net-mgmt/driftnet/files/patch-configure.ac

@@ -1,4 +1,4 @@
---- configure.ac.orig	2018-09-15 19:08:05 UTC
+--- configure.ac.orig	2019-10-19 17:01:57 UTC
 +++ configure.ac
 @@ -22,7 +22,7 @@ build_linux=no
  build_mac=no
@@ -9,3 +9,12 @@
          build_linux=yes
          ;;
      cygwin*|mingw*)
+@@ -69,7 +69,7 @@ AC_ARG_ENABLE([debug],
+     [enable_debug=yes])
+ 
+ if test "x$enable_debug" = xyes; then
+-    CFLAGS="-O2 -g -DDEBUG"
++    CFLAGS+="-O2 -g -DDEBUG"
+ else
+ 	CFLAGS="-O2 -DNDEBUG"
+ fi