kbuild: link vmlinux.o before kallsyms passes

link vmlinux.o so we may report section mismatch bugs before
we start with the real link - that may error out.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Makefile

@@ -798,7 +798,7 @@ define rule_vmlinux-modpost
 endef
 
 # vmlinux image - including updated kernel symbols
-vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) $(kallsyms.o) vmlinux.o FORCE
+vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o $(kallsyms.o) FORCE
 ifdef CONFIG_HEADERS_CHECK
 	$(Q)$(MAKE) -f $(srctree)/Makefile headers_check
 endif
@@ -809,7 +809,9 @@ endif
 	$(call if_changed_rule,vmlinux__)
 	$(Q)rm -f .old_version
 
-vmlinux.o: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) $(kallsyms.o) FORCE
+# build vmlinux.o first to catch section mismatch errors early
+$(kallsyms.o): vmlinux.o
+vmlinux.o: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) FORCE
 	$(call if_changed_rule,vmlinux-modpost)
 
 # The actual objects are generated when descending,