[PATCH] msdos partitions: fix logic error in AIX detection

Correct the AIX magic check to let 'echo > /dev/sdb' actually work.
Signed-off-by: Olaf Hering <olh@suse.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/partitions/msdos.c

@@ -68,10 +68,10 @@ static int aix_magic_present(unsigned char *p, struct block_device *bdev)
 	unsigned char *d;
 	int slot, ret = 0;
 
-	if (p[0] != AIX_LABEL_MAGIC1 &&
-		p[1] != AIX_LABEL_MAGIC2 &&
-		p[2] != AIX_LABEL_MAGIC3 &&
-		p[3] != AIX_LABEL_MAGIC4)
+	if (!(p[0] == AIX_LABEL_MAGIC1 &&
+		p[1] == AIX_LABEL_MAGIC2 &&
+		p[2] == AIX_LABEL_MAGIC3 &&
+		p[3] == AIX_LABEL_MAGIC4))
 		return 0;
 	/* Assume the partition table is valid if Linux partitions exists */
 	for (slot = 1; slot <= 4; slot++, pt++) {