This replaces "the the" with "the" in various comments.

Tested by rebuilding.  This didn't test the solib-dsbt.c change, but
it looks harmless.

gdb/ChangeLog
2019-01-17  Tom Tromey  <tromey@bapiya>

	* valprint.c: Replace "the the" with "the".
	* symtab.c: Replace "the the" with "the".
	* solib.c: Replace "the the" with "the".
	* solib-dsbt.c: Replace "the the" with "the".
	* linespec.c: Replace "the the" with "the".
	* dwarf2loc.h: Replace "the the" with "the".
	* amd64-windows-tdep.c: Replace "the the" with "the".
	* aarch64-tdep.c: Replace "the the" with "the".