Documentation: vm/memory-model: eliminate duplicated word

Drop the doubled word "the".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Mike Rapoport <rppt@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20200707180414.10467-20-rdunlap@infradead.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/vm/memory-model.rst

@@ -159,7 +159,7 @@ frame. Inside a section, the PFN is the index to the array of pages.
 The sparse vmemmap uses a virtually mapped memory map to optimize
 pfn_to_page and page_to_pfn operations. There is a global `struct
 page *vmemmap` pointer that points to a virtually contiguous array of
-`struct page` objects. A PFN is an index to that array and the the
+`struct page` objects. A PFN is an index to that array and the
 offset of the `struct page` from `vmemmap` is the PFN of that
 page.