[iproute2] iproute2: Add VF spoofchk command description to ip-link.8 man page

From: Greg Rose <redacted>

Add documentation for the ip link set spoof checking option.  The
expanded text section explaining the VF commands was missing this
text.

Signed-off-by: Greg Rose <redacted>
Signed-off-by: Jeff Kirsher <redacted>
---
 man/man8/ip-link.8 |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/man/man8/ip-link.8 b/man/man8/ip-link.8
index e1eb948..8c63584 100644
--- a/man/man8/ip-link.8
+++ b/man/man8/ip-link.8

@@ -301,6 +301,10 @@ as 0 disables VLAN tagging and filtering for the VF.
 Setting this parameter to 0 disables rate limiting. The
 .B vf
 parameter must be specified.
+
+.sp
+.BI spoofchk " on|off"
+- turn packet spoof checking on or off for the specified VF.
 .in -8
 
 .TP