[PATCH][ld/testsuite] Fix sysroot-prefix.exp on Windows.

[Nick Clifton]

Hi Igor,

> ld/ChangeLog
> 
> 	testsuite/ld-scripts/sysroot-prefix.exp
> 	(get_base_dir_for_scripts): New function.
> 	(run_sysroot_prefix_test): Use get_base_dir_for_scripts.

Approved - please apply.  (Sorry for the delay in reviewing).

Cheers
  Nick