net: chelsio: Add a missing check on cudg_get_buffer

cudbg_collect_hw_sched() could fail when the function cudg_get_buffer()
returns an error. The fix adds a check to the latter function returning
error on failure
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c

@@ -1229,6 +1229,10 @@ int cudbg_collect_hw_sched(struct cudbg_init *pdbg_init,
 
 	rc = cudbg_get_buff(pdbg_init, dbg_buff, sizeof(struct cudbg_hw_sched),
 			    &temp_buff);
+
+	if (rc)
+		return rc;
+
 	hw_sched_buff = (struct cudbg_hw_sched *)temp_buff.data;
 	hw_sched_buff->map = t4_read_reg(padap, TP_TX_MOD_QUEUE_REQ_MAP_A);
 	hw_sched_buff->mode = TIMERMODE_G(t4_read_reg(padap, TP_MOD_CONFIG_A));