x86/extable: Remove unused declaration fixup_bug()

Commit 15a416e8 ("x86/entry: Treat BUG/WARN as NMI-like entries")
removed the implementation but left the declaration.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240816102219.883297-1-yuehaibing@huawei.com

arch/x86/include/asm/extable.h

@@ -37,7 +37,6 @@ struct pt_regs;
 
 extern int fixup_exception(struct pt_regs *regs, int trapnr,
 			   unsigned long error_code, unsigned long fault_addr);
-extern int fixup_bug(struct pt_regs *regs, int trapnr);
 extern int ex_get_fixup_type(unsigned long ip);
 extern void early_fixup_exception(struct pt_regs *regs, int trapnr);