Revert "percpu: add __percpu to SHIFT_PERCPU_PTR"

This reverts commit 825dbc6f.

I mistakenly applied this and only now have thought about it a little
more and had time to evaluate a kbuild error for dmaengine.

Once we're calling RELOC_HIDE, we're moving back into the __kernel
address space and letting users interact with the actual memory address
rather than in __percpu which is before adding the offsets.
Signed-off-by: Dennis Zhou <dennis@kernel.org>

include/linux/percpu-defs.h

@@ -229,7 +229,7 @@ do {									\
  * pointer value.  The weird cast keeps both GCC and sparse happy.
  */
 #define SHIFT_PERCPU_PTR(__p, __offset)					\
-	RELOC_HIDE((typeof(*(__p)) __kernel __percpu __force *)(__p), (__offset))
+	RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset))
 
 #define per_cpu_ptr(ptr, cpu)						\
 ({									\