[RTL]: RtlGetFullPathName_Ustr: Do not upcase the drive letter in the source string (that should not be modified), but use a temporary variable.

git-svn-id: svn://svn.reactos.org/reactos/trunk/reactos@65533 97493ccd-5924-5043-b1f5-66cb403b36ce
Fix the fix.

git-svn-id: svn://svn.reactos.org/reactos/trunk/reactos@65534 97493ccd-5924-5043-b1f5-66cb403b36ce
Fix the fix of the fix (yes, really!) Also, Hervé, I'm not really convinced you need to upcase the first letter in the RtlPathTypeDriveAbsolute case. Can you recheck that (and if unneeded, remove the commented line)?

git-svn-id: svn://svn.reactos.org/reactos/trunk/reactos@65535 97493ccd-5924-5043-b1f5-66cb403b36ce