METALS-Metals buckle as 'risk off', strong dollar bite

(Adds Shanghai closing prices, updates London prices) By Melanie Burton MELBOURNE, Feb 6 (Reuters) - London nickel fell sharply on Tuesday, leading the base metals complex lower as "risk off" sentiment soured share markets and safe-haven buying lifted the dollar. The dollar has risen as a rout in global equities prompted anxious investors to cut exposure to riskier assets and seek shelter in the relative safety of the greenback. A stronger dollar makes commodities more expensive fo