ARC: module: Fix !CONFIG_ARC_DW2_UNWIND builds

commit d65283f7b695b5 added mod->arch.secstr under
CONFIG_ARC_DW2_UNWIND, but used it unconditionally which broke builds
when the option was disabled. Fix that by adjusting the #ifdef guard.

And while at it add a missing guard (for unwinder) in module.c as well

Reported-by: Waldemar Brodkorb <[e-mail]>
Cc: [e-mail] #4.9
Fixes: d65283f7b695b5 ("ARC: module: elide loop to save reference to .eh_frame")
Tested-by: Anton Kolesov <[e-mail]>
Reviewed-by: Alexey Brodkin <[e-mail]>
[abrodkin: provided fixlet to Kconfig per failure in allnoconfig build]
Signed-off-by: Vineet Gupta <[e-mail]>

arch/arc/Kconfig

···
 	select HAVE_KPROBES
 	select HAVE_KRETPROBES
 	select HAVE_MEMBLOCK
-	select HAVE_MOD_ARCH_SPECIFIC if ARC_DW2_UNWIND
+	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_OPROFILE
 	select HAVE_PERF_EVENTS
 	select HANDLE_DOMAIN_IRQ

arch/arc/include/asm/module.h

···
 
 #include <asm-generic/module.h>
 
-#ifdef CONFIG_ARC_DW2_UNWIND
 struct mod_arch_specific {
+#ifdef CONFIG_ARC_DW2_UNWIND
 	void *unw_info;
 	int unw_sec_idx;
+#endif
 	const char *secstr;
 };
-#endif
 
 #define MODULE_PROC_FAMILY "ARC700"
 

arch/arc/kernel/module.c

···
 #ifdef CONFIG_ARC_DW2_UNWIND
 	mod->arch.unw_sec_idx = 0;
 	mod->arch.unw_info = NULL;
-	mod->arch.secstr = secstr;
 #endif
+	mod->arch.secstr = secstr;
 	return 0;
 }
 
···
 
 	}
 
+#ifdef CONFIG_ARC_DW2_UNWIND
 	if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0)
 		module->arch.unw_sec_idx = tgtsec;
+#endif
 
 	return 0;