Documentation: fix typo in CodingStyle

Simple typo: "it" for "is".
Signed-off-by: Manuel Pégourié-Gonnard <mpg@elzevir.fr>
Cc: Trivial Patch Monkey <trivial@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/CodingStyle

@@ -430,7 +430,7 @@ The rationale for using gotos is:
 		return result;
 	}
 
-A common type of bug to be aware of it "one err bugs" which look like this:
+A common type of bug to be aware of is "one err bugs" which look like this:
 
 	err:
 		kfree(foo->bar);