"histfit" function does not output any measurements related to the fitted distribution. You can use either "fitdist" function or "distributionFitter" GUI tool for the same.
Correlation coefficient measures correlation between two variables and may not have relevance in this context. If you are referring to a measure of goodness of fit, both the above functions provide log-likelihood values ( https://en.wikipedia.org/wiki/Likelihood_function). You can access this value from the result as shown below.
pd = fitdist(data,'normal')
pd.negloglik
