package/pkg-generic: store real version in legal manifest

The legal manifest currently stores the $(PKG)_VERSION variable.
However, that variable undergoes a set of changes so that it is
suitable for creating files and Makefile rules; that new value
is purely a technical, internal detail of how Buildroot handles
things.

In the legal manifest, we need access to the real value for the
version, as this is what will allow actual references to the
upstream package. If the version string is mangled, like slashes
replaced with underscores, this introduces ambiguities as to what
exactly the version is.

In Buildroot, there is no package, with a constant version, that
exhibits that issue; for those packages where it is possible to
set a custom git tree and version, like linux or uboot, such a
custom tree can have tags with a slash (not a colon or a space,
forbidden by git); packages in a br2-external can also use such
version strings as well.

The packages that do have such versions are not legion, but they
do exist. For example, Apache's ant buildsystem does use a slash
in their reelase tags, like rel/1.10.15:
    https://github.com/apache/ant/tags

Change the legal manifest to include the actual, original value
as was set in the .mk file.

Signed-off-by: Yann E. MORIN <yann.morin@orange.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 686694792b06b11b2cef0acf28d81e25a280cb72)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/pkg-generic.mk

@@ -1193,7 +1193,7 @@ else
 endif # other packages
 
 endif # redistribute
-	@$$(call legal-manifest,$$(call UPPERCASE,$(4)),$$($(2)_RAWNAME),$$($(2)_VERSION),$$(subst $$(space)$$(comma),$$(comma),$$($(2)_LICENSE)),$$($(2)_MANIFEST_LICENSE_FILES),$$($(2)_ACTUAL_SOURCE_TARBALL),$$($(2)_ACTUAL_SOURCE_SITE),$$(call legal-deps,$(1)))
+	@$$(call legal-manifest,$$(call UPPERCASE,$(4)),$$($(2)_RAWNAME),$$($(2)_DL_VERSION),$$(subst $$(space)$$(comma),$$(comma),$$($(2)_LICENSE)),$$($(2)_MANIFEST_LICENSE_FILES),$$($(2)_ACTUAL_SOURCE_TARBALL),$$($(2)_ACTUAL_SOURCE_SITE),$$(call legal-deps,$(1)))
 endif # ifneq ($$(call qstrip,$$($(2)_SOURCE)),)
 	$$(foreach hook,$$($(2)_POST_LEGAL_INFO_HOOKS),$$(call $$(hook))$$(sep))