scripts/kconfig: allow building with make 3.80 again

Documentation/Changes still lists this as the minimal required version,
so it ought to remain usable for the time being.

Fixes: d2036f30 ("scripts/kconfig/Makefile: Allow KBUILD_DEFCONFIG to be a target")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michal Marek <mmarek@suse.com>

scripts/kconfig/Makefile

@@ -96,13 +96,15 @@ savedefconfig: $(obj)/conf
 defconfig: $(obj)/conf
 ifeq ($(KBUILD_DEFCONFIG),)
 	$< $(silent) --defconfig $(Kconfig)
-else ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)),)
+else
+ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)),)
 	@$(kecho) "*** Default configuration is based on '$(KBUILD_DEFCONFIG)'"
 	$(Q)$< $(silent) --defconfig=arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG) $(Kconfig)
 else
 	@$(kecho) "*** Default configuration is based on target '$(KBUILD_DEFCONFIG)'"
 	$(Q)$(MAKE) -f $(srctree)/Makefile $(KBUILD_DEFCONFIG)
 endif
+endif
 
 %_defconfig: $(obj)/conf
 	$(Q)$< $(silent) --defconfig=arch/$(SRCARCH)/configs/$@ $(Kconfig)