enic: Grammar s/an negative/a negative/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cisco/enic/enic_clsf.c

@@ -15,7 +15,7 @@
  *	@rq: rq number to steer to
  *
  * This function returns filter_id(hardware_id) of the filter
- * added. In case of error it returns an negative number.
+ * added. In case of error it returns a negative number.
  */
 int enic_addfltr_5t(struct enic *enic, struct flow_keys *keys, u16 rq)
 {