stm32mp1: rng: remove superfluous assignment

We should not assign a value that is overwritten before use.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/drivers/rng/stm32mp1_rng.c b/drivers/rng/stm32mp1_rng.c
index dab3b99..e0f0a66 100644
--- a/drivers/rng/stm32mp1_rng.c
+++ b/drivers/rng/stm32mp1_rng.c
@@ -33,7 +33,7 @@
 
 static int stm32_rng_read(struct udevice *dev, void *data, size_t len)
 {
-	int retval = 0, i;
+	int retval, i;
 	u32 sr, count, reg;
 	size_t increment;
 	struct stm32_rng_platdata *pdata = dev_get_platdata(dev);