nios2: fix __get_user()

[ Upstream commit 2e29f50a ]

a) should not leave crap on fault
b) should _not_ require access_ok() in any cases.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

arch/nios2/include/asm/uaccess.h

@@ -142,7 +142,7 @@ extern long strnlen_user(const char __user *s, long n);
 
 #define __get_user_unknown(val, size, ptr, err) do {			\
 	err = 0;							\
-	if (copy_from_user(&(val), ptr, size)) {			\
+	if (__copy_from_user(&(val), ptr, size)) {			\
 		err = -EFAULT;						\
 	}								\
 	} while (0)
@@ -169,7 +169,7 @@ do {									\
 	({								\
 	long __gu_err = -EFAULT;					\
 	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);		\
-	unsigned long __gu_val;						\
+	unsigned long __gu_val = 0;					\
 	__get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
 	(x) = (__force __typeof__(x))__gu_val;				\
 	__gu_err;							\