treewide: replace $(STAGING_DIR)/host and $(HOST_BUILD_PREFIX) with $(STAGING_DIR_HOSTPKG)

As both LEDE and OpenWrt have STAGING_DIR_HOSTPKG now, we can start to rely
on it. See 73b7f55424 for more information on
STAGING_DIR_HOSTPKG.

STAGING_DIR_HOSTPKG won't actually be changed before the first LEDE release
(it is equivalent to $(STAGING_DIR)/host), so this simple search/replace
cleanup is safe to apply. Doing this cleanup now will be useful for the
Gluon project (an OpenWrt/LEDE based firmware framework) for experimenting
with modifying STAGING_DIR_HOSTPKG before doing this in the LEDE upstream.

Also fixes a typo in the dbus Makefile ("STAGIND_DIR").

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

lang/perl/Makefile

@@ -35,7 +35,7 @@ PKG_BUILD_PARALLEL:=1
 HOST_BUILD_PARALLEL:=1
 
 # Variables used during configuration/build
-HOST_PERL_PREFIX:=$(STAGING_DIR)/host/usr
+HOST_PERL_PREFIX:=$(STAGING_DIR_HOSTPKG)/usr
 
 # Filter -g3, it will break Compress-Raw-Zlib
 TARGET_CFLAGS_PERL:=$(patsubst -g3,-g,$(TARGET_CFLAGS))

lang/perl/perlmod.mk

@@ -4,12 +4,12 @@
 PERL_VERSION:=5.22
 
 # Build environment
-HOST_PERL_PREFIX:=$(STAGING_DIR)/host/usr
+HOST_PERL_PREFIX:=$(STAGING_DIR_HOSTPKG)/usr
 ifneq ($(CONFIG_USE_GLIBC),)
 	EXTRA_LIBS:=bsd
 	EXTRA_LIBDIRS:=$(STAGING_DIR)/lib
 endif
-PERL_CMD:=$(STAGING_DIR)/host/usr/bin/perl$(PERL_VERSION).0
+PERL_CMD:=$(STAGING_DIR_HOSTPKG)/usr/bin/perl$(PERL_VERSION).0
 
 MOD_CFLAGS_PERL:=-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 $(TARGET_CFLAGS) $(TARGET_CPPFLAGS)
 ifdef CONFIG_PERL_THREADS
@@ -26,7 +26,7 @@ define perlmod/host/relink
 	rm -f $(1)/Makefile.aperl
 	$(MAKE) -C $(1) perl
 	$(CP) $(1)/perl $(PERL_CMD)
-	$(CP) $(1)/perl $(STAGING_DIR)/host/usr/bin/perl
+	$(CP) $(1)/perl $(STAGING_DIR_HOSTPKG)/usr/bin/perl
 endef
 
 define perlmod/host/Configure