crypto: omap - Drop obsolete PageSlab check

As it is now legal to call flush_dcache_page on slab pages we
no longer need to do the check in the omap driver.  This patch
also uses flush_dcache_page instead of flush_kernel_dcache_page
because the page we're writing to could be anything.
Reported-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-crypto.c

@@ -183,8 +183,7 @@ static void omap_crypto_copy_data(struct scatterlist *src,
 
 		memcpy(dstb, srcb, amt);
 
-		if (!PageSlab(sg_page(dst)))
-			flush_kernel_dcache_page(sg_page(dst));
+		flush_dcache_page(sg_page(dst));
 
 		kunmap_atomic(srcb);
 		kunmap_atomic(dstb);