Fix `PREFIX` and other paths

packages/iproute2/Makefile.patch

@@ -0,0 +1,28 @@
+--- a/Makefile
++++ b/Makefile
+@@ -12,18 +12,18 @@
+ MAKEFLAGS += --no-print-directory
+ endif
+ 
+-PREFIX?=/usr
++PREFIX?=@TERMUX_PREFIX@
+ LIBDIR?=$(PREFIX)/lib
+-SBINDIR?=/sbin
+-CONFDIR?=/etc/iproute2
+-NETNS_RUN_DIR?=/var/run/netns
+-NETNS_ETC_DIR?=/etc/netns
++SBINDIR?=$(PREFIX)/sbin
++CONFDIR?=$(PREFIX)/etc/iproute2
++NETNS_RUN_DIR?=$(PREFIX)/var/run/netns
++NETNS_ETC_DIR?=$(PREFIX)/etc/netns
+ DATADIR?=$(PREFIX)/share
+ HDRDIR?=$(PREFIX)/include/iproute2
+ DOCDIR?=$(DATADIR)/doc/iproute2
+ MANDIR?=$(DATADIR)/man
+-ARPDDIR?=/var/lib/arpd
+-KERNEL_INCLUDE?=/usr/include
++ARPDDIR?=$(PREFIX)/var/lib/arpd
++KERNEL_INCLUDE?=$(PREFIX)/include
+ BASH_COMPDIR?=$(DATADIR)/bash-completion/completions
+ 
+ # Path to db_185.h include

packages/iproute2/build.sh

@@ -7,7 +7,6 @@ TERMUX_PKG_SRCURL=https://www.kernel.org/pub/linux/utils/net/iproute2/iproute2-$
 TERMUX_PKG_SHA256=38e3e4a5f9a7f5575c015027a10df097c149111eeb739993128e5b2b35b291ff
 TERMUX_PKG_DEPENDS="libandroid-glob, libandroid-support"
 TERMUX_PKG_BUILD_IN_SRC=true
-TERMUX_PKG_EXTRA_MAKE_ARGS="DESTDIR=${TERMUX_PREFIX} PREFIX="
 
 termux_step_pre_configure() {
 	CFLAGS+=" -fPIC"

packages/iproute2/misc-arpd.c.patch

@@ -0,0 +1,11 @@
+--- a/misc/arpd.c
++++ b/misc/arpd.c
+@@ -39,7 +39,7 @@
+ #include "rt_names.h"
+ 
+ DB	*dbase;
+-char	*dbname = "/var/lib/arpd/arpd.db";
++char	*dbname = "@TERMUX_PREFIX@/var/lib/arpd/arpd.db";
+ 
+ int	ifnum;
+ int	*ifvec;