fix(st-clock): correct stm32_clk_parse_fdt_by_name

The fdt_getprop() function sets the length to -1 if the property is not
found. We should then not use it later in stm32_clk_parse_fdt_by_name()
in that case. Directly set *nb to 0U and return 0 if the property is not
found.

Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Change-Id: I19c5c953f392cdc768e0b1f3f240fc99a73a049c
diff --git a/drivers/st/clk/clk-stm32-core.c b/drivers/st/clk/clk-stm32-core.c
index 458df93..e1b6940 100644
--- a/drivers/st/clk/clk-stm32-core.c
+++ b/drivers/st/clk/clk-stm32-core.c
@@ -1073,12 +1073,15 @@
 	uint32_t i;
 
 	cell = fdt_getprop(fdt, node, name, &len);
-	if (cell != NULL) {
-		for (i = 0; i < ((uint32_t)len / sizeof(uint32_t)); i++) {
-			uint32_t val = fdt32_to_cpu(cell[i]);
+	if (cell == NULL) {
+		*nb = 0U;
+		return 0;
+	}
+
+	for (i = 0; i < ((uint32_t)len / sizeof(uint32_t)); i++) {
+		uint32_t val = fdt32_to_cpu(cell[i]);
 
-			tab[i] = val;
-		}
+		tab[i] = val;
 	}
 
 	*nb = (uint32_t)len / sizeof(uint32_t);