drivers/video/pxa168fb.c: add missing clk_put

Add a label for error-handling code in the case where only clk_get has
succeeded.  Rename the label failed to be consistent with the rest.

A simplified version of the semantic match that finds the missing clk_put
is as follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@r exists@
expression e1,e2;
statement S;
@@

e1 = clk_get@p1(...);
... when != e1 = e2
    when != clk_put(e1)
    when any
if (...) { ... when != clk_put(e1)
               when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
 } else S
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>