kbuild: Fix a typo in documentation

Signed-off-by: Warren Turkal <wt@penguintechs.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Documentation/kbuild/modules.txt

@@ -470,7 +470,7 @@ build.
 
 	Sometimes, an external module uses exported symbols from
 	another external module. kbuild needs to have full knowledge of
-	all symbols to avoid spliitting out warnings about undefined
+	all symbols to avoid spitting out warnings about undefined
 	symbols. Three solutions exist for this situation.
 
 	NOTE: The method with a top-level kbuild file is recommended