powerpc/kuap: Remove unused inline function __kuap_assert_locked()

commit 2341964e ("powerpc/kuap: Remove __kuap_assert_locked()")
left behind this one, remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220311130017.22936-1-yuehaibing@huawei.com

arch/powerpc/include/asm/kup.h

@@ -52,7 +52,6 @@ __bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
 	return false;
 }
 
-static inline void __kuap_assert_locked(void) { }
 static inline void __kuap_lock(void) { }
 static inline void __kuap_save_and_lock(struct pt_regs *regs) { }
 static inline void kuap_user_restore(struct pt_regs *regs) { }