mm: fix typos in comments

Fix ~94 single-word typos in locking code comments, plus a few
very obvious grammar mistakes.

Link: https://lkml.kernel.org/r/20210322212624.GA1963421@gmail.com
Link: https://lore.kernel.org/r/20210322205203.GB1959563@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index ea74da3..6c0185f 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -667,7 +667,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 		 *
 		 * The page table that maps the page has been already unlinked
 		 * from the page table tree and this process cannot get
-		 * an additinal pin on the page.
+		 * an additional pin on the page.
 		 *
 		 * New pins can come later if the page is shared across fork,
 		 * but not from this process. The other process cannot write to