textsearch: fix kernel-doc warnings and add kernel-api section

Make lib/textsearch.c usable as kernel-doc.
Add textsearch() function family to kernel-api documentation.
Fix kernel-doc warnings in <linux/textsearch.h>:
  ../include/linux/textsearch.h:65: warning: Incorrect use of kernel-doc format:
	* get_next_block - fetch next block of data
  ../include/linux/textsearch.h:82: warning: Incorrect use of kernel-doc format:
	* finish - finalize/clean a series of get_next_block() calls

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/core-api/kernel-api.rst b/Documentation/core-api/kernel-api.rst
index ff335f8..92f3000 100644
--- a/Documentation/core-api/kernel-api.rst
+++ b/Documentation/core-api/kernel-api.rst
@@ -136,6 +136,19 @@
 .. kernel-doc:: lib/list_sort.c
    :export:
 
+Text Searching
+--------------
+
+.. kernel-doc:: lib/textsearch.c
+   :doc: ts_intro
+
+.. kernel-doc:: lib/textsearch.c
+   :export:
+
+.. kernel-doc:: include/linux/textsearch.h
+   :functions: textsearch_find textsearch_next \
+               textsearch_get_pattern textsearch_get_pattern_len
+
 UUID/GUID
 ---------