RFR (S) 8232168: Fix non wide char canonicalization on Windows

[Schmelter, Ralf]

Hello,

this is a small change which fixes the some problems with the canonicalize() method in canonicalize_md.c. Currently it lets the wcanonicalize() method do the  work for path lengths > MAX_PATH. This change always calls the wcanonicalize() method, since the old implementation doesn't work for all path lengths <= MAX_PATH. In addition the canonicalizeWithPrefix() method has been removed, since it seems to be not used anymore.

Bug report: https://bugs.openjdk.java.net/browse/JDK-8232168
Webrev: http://cr.openjdk.java.net/~rschmelter/webrevs/8232168/webrev.0/

Best regards,
Ralf