make check report error on free variable 'yas-snippet-dirs'

[m00nlight]

The error message

Checking haskell-yas.el...
Scanning haskell-yas.el...
Scanning haskell-yas.el...done
Checking haskell-yas.el...OK

In toplevel form:
haskell-yas.el:60:17:Error: assignment to free variable `yas-snippet-dirs'
make: *** [check-haskell-yas] Error 1

[purcell]

Thanks. The check target is apparently turning a byte-compilation warning into an error, and I was reluctant to hide those particular warnings: see #356. But nonetheless, this needs to be fixed because it breaks the build, so I'll take care of it.

[purcell]

Closed in 2e9e5a6, in which I applied @Fanael's fix from #356. Sorry about this.