x86/pkeys: Clean up arch_set_user_pkey_access() declaration

arch_set_user_pkey_access() was declared two times in the header.

Remove the 2nd declaration.
Suggested-by: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220331180554.2945884-1-ira.weiny@intel.com

arch/x86/include/asm/pkeys.h

@@ -118,8 +118,6 @@ int mm_pkey_free(struct mm_struct *mm, int pkey)
 	return 0;
 }
 
-extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
-		unsigned long init_val);
 extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 		unsigned long init_val);