Fix printing of directory name on gn clean failure

The 'gn clean' code that detects whether something is a build directory
was, on Windows, printing a wchar_t* string using %s with a char*
format string. This means that only the drive letter gets printed.
Fixed by using FilePathToUTF8().

Running /analyze on gn confirmed that this is the only bug of its type
and found a few other more minor glitches, filed as part of the
referenced bug.

BUG=643842

Review-Url: https://codereview.chromium.org/2308113002
Cr-Original-Commit-Position: refs/heads/master@{#416651}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e17ac37d6c181f2d4ec5ac51eda4717af3505596
1 file changed
tree: ef536d0d115978fc70d80c50c8416152de10c581
  1. tools/