shl: handle pathconf() errors

It can return -1 (feature not supported, denied by a security module, etc.),
resulting in wrong allocation later on.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
(remove superfluous errno-checks)
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

src/kmscon_module.c

@@ -181,7 +181,7 @@ void kmscon_load_modules(void)
 {
 	int ret;
 	DIR *ent;
-	struct dirent *buf, *de;
+	struct dirent *buf = NULL, *de;
 	char *file;
 	struct kmscon_module *mod;
 

src/shl_misc.h

@@ -52,9 +52,13 @@ static inline int shl_dirent(const char *path, struct dirent **ent)
 {
 	size_t len;
 	struct dirent *tmp;
+	long name_max;
 
-	len = offsetof(struct dirent, d_name) +
+	name_max = pathconf(path, _PC_NAME_MAX);
-					pathconf(path, _PC_NAME_MAX) + 1;
+	if (name_max < 0)
+		return -errno;
+
+	len = offsetof(struct dirent, d_name) + name_max + 1;
 	tmp = malloc(len);
 	if (!tmp)
 		return -ENOMEM;