bcache: Fix building error on MIPS

This patch try to fix the building error on MIPS. The reason is MIPS
has already defined the PTR macro, which conflicts with the PTR macro
in include/uapi/linux/bcache.h.

[fixed by mlyle: corrected a line-length issue]

Cc: [e-mail]
Signed-off-by: Huacai Chen <[e-mail]>
Reviewed-by: Michael Lyle <[e-mail]>
Signed-off-by: Michael Lyle <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/md/bcache/alloc.c

···
 		if (b == -1)
 			goto err;
 
-		k->ptr[i] = PTR(ca->buckets[b].gen,
+		k->ptr[i] = MAKE_PTR(ca->buckets[b].gen,
 				bucket_to_sector(c, b),
 				ca->sb.nr_this_dev);
 

drivers/md/bcache/extents.c

···
 		return false;
 
 	for (i = 0; i < KEY_PTRS(l); i++)
-		if (l->ptr[i] + PTR(0, KEY_SIZE(l), 0) != r->ptr[i] ||
+		if (l->ptr[i] + MAKE_PTR(0, KEY_SIZE(l), 0) != r->ptr[i] ||
 		    PTR_BUCKET_NR(b->c, l, i) != PTR_BUCKET_NR(b->c, r, i))
 			return false;
 

drivers/md/bcache/journal.c

···
 			continue;
 
 		ja->cur_idx = next;
-		k->ptr[n++] = PTR(0,
+		k->ptr[n++] = MAKE_PTR(0,
 				  bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
 				  ca->sb.nr_this_dev);
 	}

include/uapi/linux/bcache.h

···
 
 #define PTR_CHECK_DEV			((1 << PTR_DEV_BITS) - 1)
 
-#define PTR(gen, offset, dev)						\
+#define MAKE_PTR(gen, offset, dev)					\
 	((((__u64) dev) << 51) | ((__u64) offset) << 8 | gen)
 
 /* Bkey utility code */