scripts: kernel-doc: proper handle @foo->bar()

The pattern @foo->bar() is valid, as it can be used by a
function pointer inside a struct passed as a parameter.

Right now, it causes a warning:

	./drivers/firewire/core-transaction.c:606: WARNING: Inline strong start-string without end-string.

In this specific case, the kernel-doc markup is:

	/**
	 * fw_core_remove_address_handler() - unregister an address handler
	 * @handler: callback
	 *
	 * To be called in process context.
	 *
	 * When fw_core_remove_address_handler() returns, @handler->callback() is
	 * guaranteed to not run on any CPU anymore.
	 */

With seems valid on my eyes. So, instead of trying to hack
the kernel-doc markup, let's teach it about how to handle
such things. This should likely remove lots of other similar
warnings as well.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/48b46426d7bf6ff7529f20e5718fbf4e9758e62c.1586881715.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc

@@ -214,6 +214,7 @@ my $type_constant2 = '\%([-_\w]+)';
 my $type_func = '(\w+)\(\)';
 my $type_param = '\@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)';
 my $type_fp_param = '\@(\w+)\(\)';  # Special RST handling for func ptr params
+my $type_fp_param2 = '\@(\w+->\S+)\(\)';  # Special RST handling for structs with func ptr params
 my $type_env = '(\$\w+)';
 my $type_enum = '\&(enum\s*([_\w]+))';
 my $type_struct = '\&(struct\s*([_\w]+))';
@@ -249,6 +250,7 @@ my @highlights_rst = (
                        [$type_member_func, "\\:c\\:type\\:`\$1\$2\$3\\\\(\\\\) <\$1>`"],
                        [$type_member, "\\:c\\:type\\:`\$1\$2\$3 <\$1>`"],
 		       [$type_fp_param, "**\$1\\\\(\\\\)**"],
+		       [$type_fp_param2, "**\$1\\\\(\\\\)**"],
                        [$type_func, "\$1()"],
                        [$type_enum, "\\:c\\:type\\:`\$1 <\$2>`"],
                        [$type_struct, "\\:c\\:type\\:`\$1 <\$2>`"],