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: stable@vger.kernel.org
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Reviewed-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NMichael Lyle <mlyle@lyle.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/md/bcache/alloc.c

@@ -490,7 +490,7 @@ int __bch_bucket_alloc_set(struct cache_set *c, unsigned reserve,
 		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

@@ -585,7 +585,7 @@ static bool bch_extent_merge(struct btree_keys *bk, struct bkey *l, struct bkey
 		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

@@ -512,7 +512,7 @@ static void journal_reclaim(struct cache_set *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

@@ -91,7 +91,7 @@ PTR_FIELD(PTR_GEN,			0,  8)
 
 #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 */