In brief "Extended error information" section, details on error
condition is referred to ftrace docs, which is written in :file:
directive instead of a proper cross-reference. Convert it.

Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 Documentation/trace/histogram.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index d158dadaa42447..340bcb5099e7a4 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -209,8 +209,8 @@ Documentation written by Tom Zanussi
 
   For some error conditions encountered when invoking a hist trigger
   command, extended error information is available via the
-  tracing/error_log file.  See Error Conditions in
-  :file:`Documentation/trace/ftrace.rst` for details.
+  tracing/error_log file.  See "Error conditions" section in
+  Documentation/trace/ftrace.rst for details.
 
 2.3. 'hist' trigger examples
 ----------------------------
-- 
An old man doll... just what I always wanted! - Clara