package: unification of use $(subst [._-], [._-], $(<PKG>_VERSION)) macro

package: unification of use $(subst [._-], [._-], $(<PKG>_VERSION)) macro

Currently, there are five packages which use 'subst' macro to change their version.

* Three of them (ebtables, icu, perl) use this macro "in place" :

   EBTABLES_SITE = http://downloads.sourceforge.net/project/ebtables/ebtables/ebtables-$(subst .,-,$(EBTABLES_VERSION))

   ICU_SOURCE = icu4c-$(subst .,_,$(ICU_VERSION))-src.tgz

   PERL_CROSS_OLD_POD = perl$(subst .,,$(PERL_CROSS_BASE_VERSION))delta.pod
   PERL_CROSS_NEW_POD = perl$(subst .,,$(PERL_VERSION))delta.pod

* Two of them (boost, libnss) use an additional variable :

   BOOST_FILE_VERSION = $(subst .,_,$(BOOST_VERSION))
   BOOST_SOURCE = boost_$(BOOST_FILE_VERSION).tar.bz2

   LIBNSS_SITE_VERSION = $(subst .,_,$(LIBNSS_VERSION))
   LIBNSS_SITE = https://ftp.mozilla.org/pub/mozilla.org/security/nss/releases/NSS_$(LIBNSS_SITE_VERSION)_RTM/src

* Additionally two packages (duma, rings) doesn't use it at all :

   DUMA_VERSION = 2_5_15
   DUMA_SITE = http://downloads.sourceforge.net/project/duma/duma/2.5.15

   RINGS_VERSION_MAJOR = 1.3.0
   RINGS_SUBDIR  = rings-v_1_3_0

This commit makes changes to use 'subst' macro "in place", in all of them.

Signed-off-by: Jerzy Grzegorek <jerzy.grzegorek@trzebnica.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>