swiotlb: Remove call to sme_active()

sme_active() is an x86-specific function so it's better not to call it from
generic code.

There's no need to mention which memory encryption feature is active, so
just use a more generic message. Besides, other architectures will have
different names for similar technology.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190806044919.10622-3-bauerman@linux.ibm.com

kernel/dma/swiotlb.c

@@ -461,8 +461,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
 		panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
 
 	if (mem_encrypt_active())
-		pr_warn_once("%s is active and system is using DMA bounce buffers\n",
-			     sme_active() ? "SME" : "SEV");
+		pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n");
 
 	mask = dma_get_seg_boundary(hwdev);