Fix ABI parsing

usr.sbin/bsdconfig/share/packages/musthavepkg.subr

@@ -1,6 +1,6 @@
 if [ ! "$_PACKAGES_MUSTHAVEPKG_SUBR" ]; then _PACKAGES_MUSTHAVEPKG_SUBR=1
 #
-# Copyright (c) 2014 Devin Teske
+# Copyright (c) 2014-2016 Devin Teske
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -45,7 +45,11 @@ f_include $BSDCFG_SHARE/mustberoot.subr
 f_musthavepkg_init()
 {
 	local funcname=f_musthavepkg_init
-	local pkg_abi_awk='$1~/^ABI/{print $NF; exit}'
+	local pkg_abi_awk=' # BEGIN-AWK
+		$1 ~ /^ABI/ && $0 = $NF, sub(/^"/, "") && sub(/".*/, "") {
+			print; found = 1; exit
+		} END { exit ! found }
+	' # END-AWK
 
 	if [ "$PKG_ABI" ]; then # Already set
 		f_dprintf "PKG_ABI=[%s]" "$PKG_ABI"