crypto: chelsio - Fix an error code in chcr_hash_dma_map()

crypto: chelsio - Fix an error code in chcr_hash_dma_map()

BugLink: http://bugs.launchpad.net/bugs/1756978
[ Upstream commit 7814f552ff826fefa5e1b24083c7a06a9378e9ef ]

The dma_map_sg() function returns zero on error and positive values on
success.  We want to return -ENOMEM on failure here and zero on success.

Fixes: 2f47d5804311 ("crypto: chelsio - Move DMA un/mapping to chcr from lld cxgb4 driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>