kbuild: do not do section mismatch checks on vmlinux in 2nd pass

We already check and warn about section mismatches from vmlinux
(build as vmlinux.o) during first pass so skip the checks
during the 2nd pass where we process modules.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index c6fcc59..1818c50 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -56,23 +56,24 @@
 
 # Step 2), invoke modpost
 #  Includes step 3,4
+modpost = scripts/mod/modpost                    \
+ $(if $(CONFIG_MODVERSIONS),-m)                  \
+ $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,)       \
+ $(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile)   \
+ $(if $(KBUILD_EXTMOD),-I $(modulesymfile))      \
+ $(if $(KBUILD_EXTMOD),-o $(modulesymfile))      \
+ $(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
+
 quiet_cmd_modpost = MODPOST $(words $(filter-out vmlinux FORCE, $^)) modules
-      cmd_modpost = scripts/mod/modpost            \
-        $(if $(CONFIG_MODVERSIONS),-m)             \
-	$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a,)  \
-	$(if $(KBUILD_EXTMOD),-i,-o) $(kernelsymfile) \
-	$(if $(KBUILD_EXTMOD),-I $(modulesymfile)) \
-	$(if $(KBUILD_EXTMOD),-o $(modulesymfile)) \
-	$(if $(KBUILD_EXTMOD)$(KBUILD_MODPOST_WARN),-w)
+      cmd_modpost = $(modpost) -s
 
 PHONY += __modpost
 __modpost: $(modules:.ko=.o) FORCE
 	$(call cmd,modpost) $(wildcard vmlinux) $(filter-out FORCE,$^)
 
 quiet_cmd_kernel-mod = MODPOST $@
-      cmd_kernel-mod = $(cmd_modpost) $@
+      cmd_kernel-mod = $(modpost) $@
 
-PHONY += vmlinux
 vmlinux.o: FORCE
 	$(call cmd,kernel-mod)