[gdb] Remove trailing "done" after "Reading symbols from" message

[gdb] Remove trailing "done" after "Reading symbols from" message

Using verbose, we get some detail on symbol loading:
...
$ gdb a.out -iex "set verbose on"
Reading symbols from a.out...
Reading in symbols for /home/vries/hello.c...done.
(gdb)
...

And using debug symtab-create, much more detail:
...
$ gdb a.out -iex "set verbose on" -iex "set debug symtab-create 1"
Reading symbols from a.out...
Reading minimal symbols of objfile /data/gdb_versions/devel/lto/a.out ...
Installing 30 minimal symbols of objfile /data/gdb_versions/devel/lto/a.out.
Done reading minimal symbols.
Creating one or more psymtabs for objfile /data/gdb_versions/devel/lto/a.out ...
Created psymtab 0x35a3de0 for module ../sysdeps/x86_64/start.S.
Created psymtab 0x353e4e0 for module init.c.
Created psymtab 0x353e560 for module ../sysdeps/x86_64/crti.S.
Created psymtab 0x353e5e0 for module /home/vries/hello.c.
Created psymtab 0x35bd530 for module elf-init.c.
Created psymtab 0x35bd5b0 for module ../sysdeps/x86_64/crtn.S.
Reading in symbols for /home/vries/hello.c...Created compunit symtab 0x354bd20 for hello.c.
done.
(gdb)
...

The "Created compunit symtab" message gets inbetween the "Reading in symbols"
and the trailing "done.". [ Strictly speaking this is a regression since
commit faa17681cc "Make gdb_flush also flush the wrap buffer", but the
same problem happens when using -batch before this commit. ]

Fix this by removing the trailing "done." altogether, such that we get:
...
Created psymtab 0x3590520 for module ../sysdeps/x86_64/crtn.S.
Reading in symbols for /home/vries/hello.c...
Created compunit symtab 0x359dd20 for hello.c.
(gdb)
...

[ Alternatively, we could fix this emitting a "Done reading in symbols" line
or some such, like is done for minimal symbols.  See above. ]

[ Note: Removing the trailing "done." for the "Reading symbols from" message
was done in commit 3453e7e409 'Clean up "Reading symbols" output'. ]

Build and reg-tested on x86_64-linux.

gdb/ChangeLog:

2020-03-06  Tom de Vries  <tdevries@suse.de>

	* psymtab.c (psymtab_to_symtab): Don't print "done.".