Created by: chenwhql

When there is a plus sign in the line, the deleted line will also be mismatched for error specification check. This PR fix this problem.

• mismatch examples: these two lines are deleted content http://ci.paddlepaddle.org/viewLog.html?buildId=282587&tab=buildLog&buildTypeId=YYTest_PrCiCpuPy2&logTab=tail

replace grep "+" with grep "^+", resolve this problem.

• success examples: the code diff keep the same as mismatch examples http://ci.paddlepaddle.org/viewLog.html?buildId=282627&buildTypeId=YYTest_PrCiCpuPy2&tab=buildLog