mm/vmalloc.c: fix typo in comment

Reported-by: Nicholas Joll <najoll@posteo.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc.c

@@ -815,7 +815,7 @@ find_vmap_lowest_match(unsigned long size,
 			}
 
 			/*
-			 * OK. We roll back and find the fist right sub-tree,
+			 * OK. We roll back and find the first right sub-tree,
 			 * that will satisfy the search criteria. It can happen
 			 * only once due to "vstart" restriction.
 			 */