net: stmmac: remove extra newline from descriptors display

One newline per line should be enough. Reduce the verbosity of
descriptors dump.
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/444f3b1dd409fdb14ed2a1ae7679a86b110dadcd.1700372381.git.baruch@tkos.co.ilSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -6203,7 +6203,6 @@ static void sysfs_display_ring(void *head, int size, int extend_desc,
 				   le32_to_cpu(p->des2), le32_to_cpu(p->des3));
 			p++;
 		}
-		seq_printf(seq, "\n");
 	}
 }