OMAP2/3 clock: omap2_clk_enable(): fix usecount decrement bug

If _omap2_clk_enable() fails, the clock's usecount must be decremented by
one no matter whether the clock has a parent or not.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/clock.c

@@ -502,12 +502,10 @@ int omap2_clk_enable(struct clk *clk)
 	ret = _omap2_clk_enable(clk);
 
 	if (ret != 0) {
+		clk->usecount--;
 		omap2_clkdm_clk_disable(clk->clkdm.ptr, clk);
-
-		if (clk->parent) {
+		if (clk->parent)
 			omap2_clk_disable(clk->parent);
-			clk->usecount--;
-		}
 	}
 
 	return ret;