docs: ftrace-uses.rst fix varios code-block directives

ftrace-uses.rst is not yet included into any toctree, but since it is
a .rst file, it is parsed by the Sphinx build. Thats, why we see some
WARNINGS:

- trace/ftrace-uses.rst:53: WARNING: Definition list ends without a blank line; unexpected unindent.
- trace/ftrace-uses.rst:89: WARNING: Inline emphasis start-string without end-string.
- trace/ftrace-uses.rst:89: WARNING: Inline emphasis start-string without end-strin

Fixing the code-block directives results in a less noisy build, but the 'not
included' WARNING will be stay:

- trace/ftrace-uses.rst: WARNING: document isn't included in any toctree
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/trace/ftrace-uses.rst

@@ -42,9 +42,9 @@ as well as what protections the callback will perform and not require
 ftrace to handle.
 
 There is only one field that is needed to be set when registering
-an ftrace_ops with ftrace::
+an ftrace_ops with ftrace:
 
-.. code-block: c
+.. code-block:: c
 
  struct ftrace_ops ops = {
        .func			= my_callback_func,
@@ -81,9 +81,9 @@ may take some time to finish.
 The callback function
 =====================
 
-The prototype of the callback function is as follows (as of v4.14)::
+The prototype of the callback function is as follows (as of v4.14):
 
-.. code-block: c
+.. code-block:: c
 
    void callback_func(unsigned long ip, unsigned long parent_ip,
                       struct ftrace_ops *op, struct pt_regs *regs);
@@ -176,7 +176,7 @@ Filtering which functions to trace
 If a callback is only to be called from specific functions, a filter must be
 set up. The filters are added by name, or ip if it is known.
 
-.. code-block: c
+.. code-block:: c
 
    int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
                          int len, int reset);
@@ -202,7 +202,7 @@ See Filter Commands in :file:`Documentation/trace/ftrace.txt`.
 
 To just trace the schedule function::
 
-.. code-block: c
+.. code-block:: c
 
    ret = ftrace_set_filter(&ops, "schedule", strlen("schedule"), 0);
 
@@ -212,7 +212,7 @@ with new functions defined by @buf, have @reset be non-zero.
 
 To remove all the filtered functions and trace all functions::
 
-.. code-block: c
+.. code-block:: c
 
    ret = ftrace_set_filter(&ops, NULL, 0, 1);
 
@@ -220,7 +220,7 @@ To remove all the filtered functions and trace all functions::
 Sometimes more than one function has the same name. To trace just a specific
 function in this case, ftrace_set_filter_ip() can be used.
 
-.. code-block: c
+.. code-block:: c
 
    ret = ftrace_set_filter_ip(&ops, ip, 0, 0);
 
@@ -237,7 +237,7 @@ be called by any function.
 An empty "notrace" list means to allow all functions defined by the filter
 to be traced.
 
-.. code-block: c
+.. code-block:: c
 
    int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
                           int len, int reset);
@@ -251,7 +251,7 @@ that match @buf to it.
 
 Clearing the "notrace" list is the same as clearing the filter list
 
-.. code-block: c
+.. code-block:: c
 
   ret = ftrace_set_notrace(&ops, NULL, 0, 1);
 
@@ -264,7 +264,7 @@ If a filter is in place, and the @reset is non-zero, and @buf contains a
 matching glob to functions, the switch will happen during the time of
 the ftrace_set_filter() call. At no time will all functions call the callback.
 
-.. code-block: c
+.. code-block:: c
 
    ftrace_set_filter(&ops, "schedule", strlen("schedule"), 1);
 
@@ -276,7 +276,7 @@ the ftrace_set_filter() call. At no time will all functions call the callback.
 
 is not the same as:
 
-.. code-block: c
+.. code-block:: c
 
    ftrace_set_filter(&ops, "schedule", strlen("schedule"), 1);