dma-buf: fix compare in WARN_ON_ONCE

Smatch pointed out this trivial typo:
drivers/dma-buf/dma-buf.c:1123 dma_buf_map_attachment()
warn: passing positive error code '16' to 'ERR_PTR'

drivers/dma-buf/dma-buf.c
1113 dma_resv_assert_held(attach->dmabuf->resv);
1114
1115 if (dma_buf_pin_on_map(attach)) {
1116 ret = attach->dmabuf->ops->pin(attach);
1117 /*
1118 * Catch exporters making buffers inaccessible even when
1119 * attachments preventing that exist.
1120 */
1121 WARN_ON_ONCE(ret == EBUSY);
^^^^^
This was probably intended to be -EBUSY?

1122 if (ret)
--> 1123 return ERR_PTR(ret);
^^^
Otherwise we will eventually crash.

1124 }
1125
1126 sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
1127 if (!sg_table)
1128 sg_table = ERR_PTR(-ENOMEM);
1129 if (IS_ERR(sg_table))
1130 goto error_unpin;
1131

Signed-off-by: Christian König <[e-mail]>
Reviewed-by: Tvrtko Ursulin <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/dma-buf/dma-buf.c

···
 		 * Catch exporters making buffers inaccessible even when
 		 * attachments preventing that exist.
 		 */
-		WARN_ON_ONCE(ret == EBUSY);
+		WARN_ON_ONCE(ret == -EBUSY);
 		if (ret)
 			return ERR_PTR(ret);
 	}