internal/routebsd: fix typo in sockAddrLen identifer name

For #70528.

Change-Id: I0db75cb998aeb299676384fe59bf241db18ebc5c
Reviewed-on: https://go-review.googlesource.com/c/go/+/646975
Reviewed-by: Cherry Mui <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: dmitshur

src/internal/routebsd/address.go

@@ -133,7 +133,7 @@ func parseInetAddr(af int, b []byte) (Addr, error) {
 		}
 		var ip [ipv6Len]byte
 		sockAddrLen := int(b[0])
-		if sockaddrLen != 0 {
+		if sockAddrLen != 0 {
 			n := off6 + ipv6Len
 			if sockAddrLen < n {
 				n = sockAddrLen