Fixes gcc '-Wunused-but-set-variable' warning:

drivers/clk/socfpga/clk-pll.c:83:6: warning: variable ‘rc’ set but
not used [-Wunused-but-set-variable]

The returned value of of_clk_add_provider() is never used, and so
can be removed.

Fixes: 97259e99bdc9 ("clk: socfpga: split clk code")
Signed-off-by: Yu Kuai <redacted>
---
 drivers/clk/socfpga/clk-pll.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/clk/socfpga/clk-pll.c b/drivers/clk/socfpga/clk-pll.c
index dcb573d44034..127cc849c5ee 100644
--- a/drivers/clk/socfpga/clk-pll.c
+++ b/drivers/clk/socfpga/clk-pll.c

@@ -80,7 +80,6 @@ static __init struct clk_hw *__socfpga_pll_init(struct device_node *node,
        const char *parent_name[SOCFPGA_MAX_PARENTS];
        struct clk_init_data init;
        struct device_node *clkmgr_np;
-       int rc;
        int err;
 
        of_property_read_u32(node, "reg", &reg);

@@ -114,7 +113,7 @@ static __init struct clk_hw *__socfpga_pll_init(struct device_node *node,
                kfree(pll_clk);
                return ERR_PTR(err);
        }
-       rc = of_clk_add_provider(node, of_clk_src_simple_get, hw_clk);
+       of_clk_add_provider(node, of_clk_src_simple_get, hw_clk);