multilib_script.bbclass: expand script name as well

multilib_script.bbclass: expand script name as well

* e.g. mozjs from meta-oe contains major version from PV in the script name
  but currently cannot use a variable there because it would be unexpanded
  in the varflag name as shown in bitbake -e (lib32-curl included for comparison)

env.lib32-curl:# $ALTERNATIVE_TARGET [2 operations]
env.lib32-curl-#   set oe-core/meta/conf/documentation.conf:66
env.lib32-curl-#     [doc] "Used by the alternatives system to create default link locations for duplicated commands."
env.lib32-curl-#   set multilib_script.bbclass:37 [__anon_40_oe_core_meta_classes_recipe_multilib_script_bbclass]
env.lib32-curl-#     [curl-config] "${bindir}/curl-config-${MULTILIB_SUFFIX}"
env.lib32-curl-# pre-expansion value:
env.lib32-curl-#   "None"
--
env.lib32-mozjs-115:# $ALTERNATIVE_TARGET [2 operations]
env.lib32-mozjs-115-#   set oe-core/meta/conf/documentation.conf:66
env.lib32-mozjs-115-#     [doc] "Used by the alternatives system to create default link locations for duplicated commands."
env.lib32-mozjs-115-#   set multilib_script.bbclass:37 [__anon_40_oe_core_meta_classes_recipe_multilib_script_bbclass]
env.lib32-mozjs-115-#     [js${MAJ_VER}-config] "${bindir}/js${MAJ_VER}-config-${MULTILIB_SUFFIX}"
env.lib32-mozjs-115-# pre-expansion value:
env.lib32-mozjs-115-#   "None"
--
env.lib32-mozjs-115-escript:# $ALTERNATIVE_TARGET [2 operations]
env.lib32-mozjs-115-escript-#   set oe-core/meta/conf/documentation.conf:66
env.lib32-mozjs-115-escript-#     [doc] "Used by the alternatives system to create default link locations for duplicated commands."
env.lib32-mozjs-115-escript-#   set multilib_script.bbclass:38 [__anon_41_oe_core_meta_classes_recipe_multilib_script_bbclass]
env.lib32-mozjs-115-escript-#     [js115-config] "/usr/bin/js115-config-${MULTILIB_SUFFIX}"
env.lib32-mozjs-115-escript-# pre-expansion value:
env.lib32-mozjs-115-escript-#   "None"

Otherwise log.do_package shows that apply_update_alternative_renames first
renames the js115-config to js115-config.mozjs-115 (default ALTERNATIVE_TARGET suffix is '.${BPN}')
and multilibscript_rename later fails:

DEBUG: Executing python function apply_update_alternative_renames
NOTE: mozjs-115: Rename /usr/bin/js115-config -> /usr/bin/js115-config.mozjs-115
DEBUG: Python function apply_update_alternative_renames finished
DEBUG: Executing shell function multilibscript_rename
mv: cannot stat 'BUILD/work/mach-oemllib32-linux-gnueabi/lib32-mozjs-115/115.2.0/package/usr/bin/js115-config': No such file or directory
WARNING: exit code 1 from a shell command.

I wonder if we actually need multilibscript_rename as apply_update_alternative_renames seems
to do the rename already.

Signed-off-by: Martin Jansa <martin.jansa@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>