i945-thinkpads-install-utilities: fix build.

Without that fix the build is stuck on the following during days on a
ThinkPad X200 with 8GiB of RAM and an Intel P8600:
    building /gnu/store/z7k1rs4j98s5zj0f9xrn1p3k1w1fmgqa-proot-static-5.3.0.drv...
    / 'check' phase

And the Guix manual says the following about -R/-RR:
    When this option is passed once, the resulting binaries require
    support for “user namespaces” in the kernel Linux; when passed
    _twice_(1), relocatable binaries fall to back to other techniques
    if user namespaces are unavailable, and essentially work
    anywhere—see below for the implications.

So by using -R instead of -RR we don't build proot-static anymore, and
we rely on the fact that most GNU/Linux distribution have namespaces
enabled (else a lot of packages like Guix or container software
would not work on them).

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
neox: fixed typo in commit message
Acked-by: Adrien Bourmault <neox@gnu.org>

resources/packages/i945-thinkpads-install-utilities/Makefile.am

@@ -40,7 +40,7 @@ GUIX_PACK_COMMAND = \
 	pack \
 	-L $(TOPDIR)/resources/guix/ \
 	-L $(TOPDIR)/resources/guix/gnuboot/patches/ \
-	-RR \
+	-R \
 	--save-provenance \
 	--system=i686-linux \
 	--symlink=/usr/local/bin/bucts=bin/bucts \