coding-style: fix mismatch of jump label name

Commit 865a1caa4b ("CodingStyle: Clarify and complete chapter 7")
renamed the label "out_buffer" to "out_free_buffer", but missed to
change this line.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/process/coding-style.rst

@@ -475,7 +475,7 @@ The rationale for using gotos is:
 				...
 			}
 			result = 1;
-			goto out_buffer;
+			goto out_free_buffer;
 		}
 		...
 	out_free_buffer: