arch/arm/mach-omap2/clock.c: add missing clk_put

Add missing call to clk_put.

A simplified version of the semantic match that finds this problem 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>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/clock.c

@@ -453,6 +453,7 @@ int __init omap2_clk_switch_mpurate_at_boot(const char *mpurate_ck_name)
 	if (IS_ERR_VALUE(r)) {
 		WARN(1, "clock: %s: unable to set MPU rate to %d: %d\n",
 		     mpurate_ck->name, mpurate, r);
+		clk_put(mpurate_ck);
 		return -EINVAL;
 	}