clk: st: Remove impossible check for of_clk_get_parent_count() < 0

The checks for < 0 are impossible now that
of_clk_get_parent_count() returns an unsigned int. Simplify the
code and update the types.

Cc: Gabriel Fernandez <gabriel.fernandez@st.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/st/clk-flexgen.c

@@ -244,10 +244,10 @@ static const char ** __init flexgen_get_parents(struct device_node *np,
 						       int *num_parents)
 {
 	const char **parents;
-	int nparents;
+	unsigned int nparents;
 
 	nparents = of_clk_get_parent_count(np);
-	if (WARN_ON(nparents <= 0))
+	if (WARN_ON(!nparents))
 		return NULL;
 
 	parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);

drivers/clk/st/clkgen-mux.c

@@ -26,10 +26,10 @@ static const char ** __init clkgen_mux_get_parents(struct device_node *np,
 						       int *num_parents)
 {
 	const char **parents;
-	int nparents;
+	unsigned int nparents;
 
 	nparents = of_clk_get_parent_count(np);
-	if (WARN_ON(nparents <= 0))
+	if (WARN_ON(!nparents))
 		return ERR_PTR(-EINVAL);
 
 	parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL);