clk: SPEAr: Vco-pll: Fix compilation warning

Currently we are getting following warning for SPEAr clk-vco-pll.

"warning: i is used uninitialized in this function."

This is because we are getting value of i by passing its pointer to another
routine.

The variables here are really not used uninitialized.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/spear/clk-vco-pll.c

@@ -147,7 +147,7 @@ static int clk_pll_set_rate(struct clk_hw *hw, unsigned long drate,
 	struct clk_pll *pll = to_clk_pll(hw);
 	struct pll_rate_tbl *rtbl = pll->vco->rtbl;
 	unsigned long flags = 0, val;
-	int i;
+	int uninitialized_var(i);
 
 	clk_pll_round_rate_index(hw, drate, NULL, &i);