[PATCH] cb710: avoid NULL pointer subtraction

[Arnd Bergmann]

From: Arnd Bergmann <arnd@xxxxxxxx>

clang-14 complains about an unusual way of converting a pointer to
an integer:

drivers/misc/cb710/sgbuf2.c:50:15: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
        return ((ptr - NULL) & 3) != 0;

Replace this with a normal cast to uintptr_t.

Fixes: 5f5bac8272be ("mmc: Driver for CB710/720 memory card reader (MMC part)")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 drivers/misc/cb710/sgbuf2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/cb710/sgbuf2.c b/drivers/misc/cb710/sgbuf2.c
index e5a4ed3701eb..a798fad5f03c 100644
--- a/drivers/misc/cb710/sgbuf2.c
+++ b/drivers/misc/cb710/sgbuf2.c
@@ -47,7 +47,7 @@ static inline bool needs_unaligned_copy(const void *ptr)
 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 	return false;
 #else
-	return ((ptr - NULL) & 3) != 0;
+	return ((uintptr_t)ptr & 3) != 0;
 #endif
 }
 
-- 
2.29.2