kbuild: Propagate LOCALVERSION= down to scripts/setlocalversion

Variables given on the make commandline are not exported to $(shell
...) commands, so run the setlocalversion script in the make rule
directly.
Signed-off-by: Michal Marek <mmarek@suse.cz>

Makefile

@@ -884,11 +884,9 @@ $(vmlinux-dirs): prepare scripts
 	$(Q)$(MAKE) $(build)=$@
 
 # Store (new) KERNELRELASE string in include/config/kernel.release
-localversion = $(shell $(CONFIG_SHELL) \
-	       $(srctree)/scripts/setlocalversion $(srctree))
 include/config/kernel.release: include/config/auto.conf FORCE
 	$(Q)rm -f $@
-	$(Q)echo $(KERNELVERSION)$(localversion) > $@
+	$(Q)echo "$(KERNELVERSION)$$($(CONFIG_SHELL) scripts/setlocalversion $(srctree))" > $@
 
 
 # Things we need to do before we recursively start building the kernel