kernel-doc: Don't try to mark up function names

We now have better automarkup in sphinx itself and, besides, this markup
was incorrect and left :c:func: gunk in the processed docs.  Sort of
discouraging that nobody ever noticed...:)

As a first step toward the removal of impenetrable regex magic from
kernel-doc it's a tiny one, but you have to start somewhere.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

scripts/kernel-doc

@@ -249,7 +249,7 @@ my @highlights_rst = (
                        [$type_member_func, "\\:c\\:type\\:`\$1\$2\$3\\\\(\\\\) <\$1>`"],
                        [$type_member, "\\:c\\:type\\:`\$1\$2\$3 <\$1>`"],
 		       [$type_fp_param, "**\$1\\\\(\\\\)**"],
-                       [$type_func, "\\:c\\:func\\:`\$1()`"],
+                       [$type_func, "\$1()"],
                        [$type_enum, "\\:c\\:type\\:`\$1 <\$2>`"],
                        [$type_struct, "\\:c\\:type\\:`\$1 <\$2>`"],
                        [$type_typedef, "\\:c\\:type\\:`\$1 <\$2>`"],