Use correct stream for process record output

Use correct stream for process record output

The process record code often emits unfiltered output.  In some cases,
this output ought to go to gdb_stderr (but see below).  In other
cases, the output is guarded by a logging variable and so ought to go
to gdb_stdlog.  This patch makes these changes.

Note that in many cases, the output to stderr is followed by a
"return -1", which is how process record indicates an error.  It seems
to me that calling error here would be preferable, because, in many
cases, that's all the caller does when it sees a -1.  However, I
haven't made this change.

This is part of PR gdb/7233.

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