powerpc: Fix duplicate const clang warning in user access code

We see a large number of duplicate const errors in the user access
code when building with llvm/clang:

  include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier
      [-Wduplicate-decl-specifier]
        ret = __get_user(c, uaddr);

The problem is we are doing const __typeof__(*(ptr)), which will hit the
warning if ptr is marked const.

Removing const does not seem to have any effect on GCC code generation.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/uaccess.h

@@ -265,7 +265,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	unsigned long __gu_val;					\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	if (!is_kernel_addr((unsigned long)__gu_addr))		\
 		might_fault();					\
@@ -279,7 +279,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	long long __gu_val;					\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	if (!is_kernel_addr((unsigned long)__gu_addr))		\
 		might_fault();					\
@@ -293,7 +293,7 @@ do {								\
 ({									\
 	long __gu_err = -EFAULT;					\
 	unsigned long  __gu_val = 0;					\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
 	might_fault();							\
 	if (access_ok(VERIFY_READ, __gu_addr, (size)))			\
 		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
@@ -305,7 +305,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	unsigned long __gu_val;					\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
 	(x) = (__force __typeof__(*(ptr)))__gu_val;			\