Redundant `return` for named returns

[code423n4]

Handle

WatchPug

Vulnerability details

Redundant code increase contract size and gas usage at deployment.

https://github.com/code-423n4/2022-01-yield/blob/e946f40239b33812e54fafc700eb2298df1a2579/contracts/ConvexStakingWrapper.sol#L310-L343

L342, return claimable is redundant.

Similar issue exists in L1LPTGateway.sol#getOutboundCalldata().

[iamsahu]

From readme:

• In general, we are not going to change our code for small gas optimizations less than 100 gas

[alcueca]

Duplicate of #60, which states a good reason to confirm this as a code quality issue, even if we don't care about the gas savings.