Remove unnecessary calls to wrap_here and gdb_flush

Various spots in gdb currently know about the wrap buffer, and so are
careful to call wrap_here to be certain that all output has been
flushed.

Now that the pager is just an ordinary stream, this isn't needed, and
a simple call to gdb_flush is enough.

Similarly, there are places where gdb prints to gdb_stderr, but first
flushes gdb_stdout.  stderr_file already flushes gdb_stdout, so these
aren't needed.

gdb/psymtab.c

@@ -1426,7 +1426,6 @@ partial_symtab::expand_dependencies (struct objfile *objfile)
 	      gdb_puts ("and ");
 	      gdb_stdout->wrap_here (0);
 	      gdb_printf ("%s...", dependencies[i]->filename);
-	      gdb_stdout->wrap_here (0);	/* Flush output */
 	      gdb_flush (gdb_stdout);
 	    }
 	  dependencies[i]->expand_psymtab (objfile);