x86: remove more uaccess_32.h complexity

I'm looking at trying to possibly merge the 32-bit and 64-bit versions
of the x86 uaccess.h implementation, but first this needs to be cleaned
up.

For example, the 32-bit version of "__copy_from_user_inatomic()" is
mostly the special cases for the constant size, and it's actually almost
never relevant.  Most users aren't actually using a constant size
anyway, and the few cases that do small constant copies are better off
just using __get_user() instead.

So get rid of the unnecessary complexity.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/futex.c

@@ -729,7 +729,7 @@ static int get_futex_value_locked(u32 *dest, u32 __user *from)
 	int ret;
 
 	pagefault_disable();
-	ret = __copy_from_user_inatomic(dest, from, sizeof(u32));
+	ret = __get_user(*dest, from);
 	pagefault_enable();
 
 	return ret ? -EFAULT : 0;