Avoid warnings about unused variables in rest and asciidoc parsers

We don't use the return value of getNestingLevel(), only its
nestingLevelsPop() semantics. Get rid of the return value and rename the
function to avoid confusion.

ctags/parsers/asciidoc.c

@@ -52,7 +52,7 @@ static NestingLevels *nestingLevels = NULL;
 *   FUNCTION DEFINITIONS
 */
 
-static NestingLevel *getNestingLevel(const int kind)
+static void popNestingLevelToKind(const int kind)
 {
 	NestingLevel *nl;
 	tagEntryInfo *e;
@@ -66,17 +66,16 @@ static NestingLevel *getNestingLevel(const int kind)
 		else
 			break;
 	}
-	return nl;
 }
 
 static void makeAsciidocTag (const vString* const name, const int kind)
 {
-	const NestingLevel *const nl = getNestingLevel(kind);
 	int r = CORK_NIL;
 
+	popNestingLevelToKind(kind);
+
 	if (vStringLength (name) > 0)
 	{
-		tagEntryInfo *parent = getEntryOfNestingLevel (nl);
 		tagEntryInfo e;
 
 		initTagEntry (&e, vStringValue (name), &(AsciidocKinds [kind]));

ctags/parsers/rest.c

@@ -49,7 +49,7 @@ static NestingLevels *nestingLevels = NULL;
 *   FUNCTION DEFINITIONS
 */
 
-static NestingLevel *getNestingLevel(const int kind)
+static void popNestingLevelToKind(const int kind)
 {
 	NestingLevel *nl;
 	tagEntryInfo *e;
@@ -63,17 +63,16 @@ static NestingLevel *getNestingLevel(const int kind)
 		else
 			break;
 	}
-	return nl;
 }
 
 static void makeRestTag (const vString* const name, const int kind)
 {
-	const NestingLevel *const nl = getNestingLevel(kind);
 	int r = CORK_NIL;
 
+	popNestingLevelToKind(kind);
+
 	if (vStringLength (name) > 0)
 	{
-		tagEntryInfo *parent = getEntryOfNestingLevel (nl);
 		tagEntryInfo e;
 
 		initTagEntry (&e, vStringValue (name), &(RestKinds [kind]));