fm10k: fix possible null pointer deref after kcalloc

When writing a new default redirection table, we needed to populate
a new RSS table using ethtool_rxfh_indir_default. We populated this
table into a region of memory allocated using kcalloc, but never checked
this for NULL. Fix this by moving the default table generation into
fm10k_write_reta. If this function is passed a table, use it. Otherwise,
generate the default table using ethtool_rxfh_indir_default, 4 at at
time.

Fixes: 0ea7fae44094 ("fm10k: use ethtool_rxfh_indir_default for default redirection table")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
index 58092e5..aca3e47 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -1927,8 +1927,7 @@
 static void fm10k_init_reta(struct fm10k_intfc *interface)
 {
 	u16 i, rss_i = interface->ring_feature[RING_F_RSS].indices;
-	struct net_device *netdev = interface->netdev;
-	u32 reta, *indir;
+	u32 reta;
 
 	/* If the Rx flow indirection table has been configured manually, we
 	 * need to maintain it when possible.
@@ -1953,16 +1952,7 @@
 	}
 
 repopulate_reta:
-	indir = kcalloc(fm10k_get_reta_size(netdev),
-			sizeof(indir[0]), GFP_KERNEL);
-
-	/* generate redirection table using the default kernel policy */
-	for (i = 0; i < fm10k_get_reta_size(netdev); i++)
-		indir[i] = ethtool_rxfh_indir_default(i, rss_i);
-
-	fm10k_write_reta(interface, indir);
-
-	kfree(indir);
+	fm10k_write_reta(interface, NULL);
 }
 
 /**