Use $(sort) here, which implicitly removes duplicates.
	Otherwise our CFLAGS are passed in via CCOPT and CFLAGS leading
	to duplicate -fhonour-copts passing.
--- libpcap-1.6.2.orig/Makefile.in	2014-07-03 00:12:49.000000000 +0200
+++ libpcap-1.6.2/Makefile.in	2014-09-12 15:12:48.567519024 +0200
@@ -61,7 +61,7 @@ DEPENDENCY_CFLAG = @DEPENDENCY_CFLAG@
 PROG=libpcap
 
 # Standard CFLAGS
-FULL_CFLAGS = $(CCOPT) $(INCLS) $(DEFS) $(CFLAGS)
+FULL_CFLAGS = $(sort $(CCOPT) $(INCLS) $(DEFS) $(CFLAGS))
 
 INSTALL = @INSTALL@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@