[analyzer] scan-view: don't ever serve absolute paths.

At one point in time scan-view allowed absolute paths to reference files
within the server root, but this doesn't seem to be used anymore, and
caused problems if a server-root-relative path actually matched an
absolute path to an existing file. This patch just treats paths as
server-root-relative all the time.

PR15843

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180715 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed