powerpc/uaccess: Swap clear_user() and __clear_user()

It is clear_user() which is expected to call __clear_user(),
not the reverse.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d8ec01fb22f33d87321451d5e5f01cb56dacaa39.1615398498.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/uaccess.h

@@ -414,21 +414,20 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
 
 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
 
-static inline unsigned long clear_user(void __user *addr, unsigned long size)
+static inline unsigned long __clear_user(void __user *addr, unsigned long size)
 {
-	unsigned long ret = size;
+	unsigned long ret;
+
 	might_fault();
-	if (likely(access_ok(addr, size))) {
-		allow_write_to_user(addr, size);
-		ret = __arch_clear_user(addr, size);
-		prevent_write_to_user(addr, size);
-	}
+	allow_write_to_user(addr, size);
+	ret = __arch_clear_user(addr, size);
+	prevent_write_to_user(addr, size);
 	return ret;
 }
 
-static inline unsigned long __clear_user(void __user *addr, unsigned long size)
+static inline unsigned long clear_user(void __user *addr, unsigned long size)
 {
-	return clear_user(addr, size);
+	return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
 }
 
 extern long strncpy_from_user(char *dst, const char __user *src, long count);