hwpoison: remove unused global variable in do_machine_check()

Remove an unused global variable mce_entry and relative operations in
do_machine_check().

Signed-off-by: Chen Yucong <[e-mail]>
Cc: Naoya Horiguchi <[e-mail]>
Cc: Wu Fengguang <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/x86/include/asm/mce.h

···
 DECLARE_PER_CPU(unsigned, mce_exception_count);
 DECLARE_PER_CPU(unsigned, mce_poll_count);
 
-extern atomic_t mce_entry;
-
 typedef DECLARE_BITMAP(mce_banks_t, MAX_NR_BANKS);
 DECLARE_PER_CPU(mce_banks_t, mce_poll_banks);
 

arch/x86/kernel/cpu/mcheck/mce.c

···
 
 #define SPINUNIT 100	/* 100ns */
 
-atomic_t mce_entry;
-
 DEFINE_PER_CPU(unsigned, mce_exception_count);
 
 struct mce_bank *mce_banks __read_mostly;
···
 	DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
 	char *msg = "Unknown";
 
-	atomic_inc(&mce_entry);
-
 	this_cpu_inc(mce_exception_count);
 
 	if (!cfg->banks)
···
 		mce_report_event(regs);
 	mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
 out:
-	atomic_dec(&mce_entry);
 	sync_core();
 }
 EXPORT_SYMBOL_GPL(do_machine_check);