Use debug_prefixed_printf_cond_nofunc in index-cache

This changes index-cache.c to use debug_prefixed_printf_cond_nofunc.
As a side effect, logs are now written to gdb_stdlog.  This is part of
PR gdb/7233.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=7233



1 file changed