kernel-doc: add support for one line inline struct member doc comments

kernel-doc supports documenting struct members "inline" since
a4c6ebede2 ("scripts/kernel-doc Allow struct arguments documentation
in struct body"). This requires the inline kernel-doc comments to have
the opening and closing comment markers (/** and */ respectively) on
lines of their own, even for short comments. For example:

	/**
	 * struct foo - struct documentation
	 */
	struct foo {
		/**
		 * @bar: member documentation
		 */
		int bar;
	};

Add support for one line inline comments:

	/**
	 * struct foo - struct documentation
	 */
	struct foo {
		/** @bar: member documentation */
		int bar;
	};

Note that mixing of the two in one doc comment is not allowed; either
both comment markers must be on lines of their own, or both must be on
the one line. This limitation keeps both the comments more uniform, and
kernel-doc less complicated.

Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/kernel-doc

@@ -421,6 +421,7 @@ my $doc_block = $doc_com . 'DOC:\s*(.*)?';
 my $doc_inline_start = '^\s*/\*\*\s*$';
 my $doc_inline_sect = '\s*\*\s*(@[\w\s]+):(.*)';
 my $doc_inline_end = '^\s*\*/\s*$';
+my $doc_inline_oneline = '^\s*/\*\*\s*(@[\w\s]+):\s*(.*)\s*\*/\s*$';
 my $export_symbol = '^\s*EXPORT_SYMBOL(_GPL)?\s*\(\s*(\w+)\s*\)\s*;';
 
 my %parameterdescs;
@@ -3024,7 +3025,16 @@ sub process_file($) {
 		}
 	    }
 	} elsif ($state == STATE_PROTO) {	# scanning for function '{' (end of prototype)
-	    if (/$doc_inline_start/) {
+	    if (/$doc_inline_oneline/) {
+		$section = $1;
+		$contents = $2;
+		if ($contents ne "") {
+		    $contents .= "\n";
+		    dump_section($file, $section, xml_escape($contents));
+		    $section = $section_default;
+		    $contents = "";
+		}
+	    } elsif (/$doc_inline_start/) {
 		$state = STATE_INLINE;
 		$inline_doc_state = STATE_INLINE_NAME;
 	    } elsif ($decl_type eq 'function') {