Reduce cmd line length for make_installer calls

Seems on Windows, we're hitting the 8k character max cmd line length,
on setups with slightly deeper src tree path locations. Shorten length
of expanded call_installer calls by putting shell script into PATH
locally.

Change-Id: If1cddab9e4e07a7c5ebfae7a4e88e43b1bc8b907
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/134938
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <thorsten.behrens@allotropia.de>

instsetoo_native/CustomTarget_install.mk

@@ -71,8 +71,9 @@ $(if $(GNUPARALLEL), \
 , \
     $(call gb_Helper_print_on_error, \
     cd $(dir $@) \
+    && PATH="$(SRCDIR)/solenv/bin:$$PATH" \
     $(foreach curpkg,$(1),\
-    && $(SRCDIR)/solenv/bin/call_installer.sh $(if $(verbose),-verbose,-quiet) $(curpkg) \
+    && call_installer.sh $(if $(verbose),-verbose,-quiet) $(curpkg) \
     ),$@.log))
 endef