This commit modifies test-crypt-scrypt.js to use a regular expression
for the function name in the error message, similar to what is done for
the error code.

The motivation for this change comes from a case where we (Red Hat)
patch OpenSSL and the memory limit checking is done in a different
function, meaning that the function name from which this error
originates differs from that when linking to the OpenSSL version shipped
with Node.js.