powerpc/kuap: Fold kuep_is_disabled() into its only user

kuep_is_disabled() was introduced by commit 91bb3082 ("powerpc/32s:
Refactor update of user segment registers") but then all users but one
were removed by commit 526d4a4c ("powerpc/32s: Do kuep_lock() and
kuep_unlock() in assembly").

Fold kuep_is_disabled() into init_new_context() which is its only user.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/b2247147c0a8c830ac82966451647850df4a64da.1689091022.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/book3s/32/kup.h

@@ -13,11 +13,6 @@
 
 extern struct static_key_false disable_kuap_key;
 
-static __always_inline bool kuep_is_disabled(void)
-{
-	return !IS_ENABLED(CONFIG_PPC_KUEP);
-}
-
 #ifdef CONFIG_PPC_KUAP
 
 #include <linux/sched.h>

arch/powerpc/mm/book3s32/mmu_context.c

@@ -71,7 +71,7 @@ int init_new_context(struct task_struct *t, struct mm_struct *mm)
 	mm->context.id = __init_new_context();
 	mm->context.sr0 = CTX_TO_VSID(mm->context.id, 0);
 
-	if (!kuep_is_disabled())
+	if (IS_ENABLED(CONFIG_PPC_KUEP))
 		mm->context.sr0 |= SR_NX;
 	if (!kuap_is_disabled())
 		mm->context.sr0 |= SR_KS;