Kbuild: append missing-syscalls to the default target list

This avoid an extra make invocation on `prepare0'.
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Kbuild

@@ -88,11 +88,13 @@ $(obj)/$(offsets-file): arch/$(SRCARCH)/kernel/asm-offsets.s Kbuild
 # 3) Check for missing system calls
 #
 
+always += missing-syscalls
+targets += missing-syscalls
+
 quiet_cmd_syscalls = CALL    $<
       cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags)
 
-PHONY += missing-syscalls
-missing-syscalls: scripts/checksyscalls.sh FORCE
+missing-syscalls: scripts/checksyscalls.sh $(offsets-file) FORCE
 	$(call cmd,syscalls)
 
 # Keep these two files during make clean

Makefile

@@ -983,7 +983,6 @@ archprepare: prepare1 scripts_basic
 
 prepare0: archprepare FORCE
 	$(Q)$(MAKE) $(build)=.
-	$(Q)$(MAKE) $(build)=. missing-syscalls
 
 # All the preparing..
 prepare: prepare0