util: Explicitly initialize auto-cleanup variables

gcc complains about potentially uninitialized variables.

Signed-off-by: Tomas Bzatek <tbzatek@redhat.com>

src/nvme/util.c

@@ -757,7 +757,7 @@ char *kv_keymatch(const char *kv, const char *key)
 static size_t read_file(const char * fname, char *buffer, size_t *bufsz)
 {
 	char   *p;
-	_cleanup_file_ FILE *file;
+	_cleanup_file_ FILE *file = NULL;
 	size_t len;
 
 	file = fopen(fname, "re");
@@ -806,7 +806,7 @@ size_t get_entity_name(char *buffer, size_t bufsz)
 
 size_t get_entity_version(char *buffer, size_t bufsz)
 {
-	_cleanup_file_ FILE *file;
+	_cleanup_file_ FILE *file = NULL;
 	size_t  num_bytes = 0;
 
 	/* /proc/sys/kernel/ostype typically contains the string "Linux" */
@@ -928,7 +928,7 @@ int nvme_uuid_from_string(const char *str, unsigned char uuid[NVME_UUID_LEN])
 
 int nvme_uuid_random(unsigned char uuid[NVME_UUID_LEN])
 {
-	_cleanup_fd_ int f;
+	_cleanup_fd_ int f = -1;
 	ssize_t n;
 
 	f = open("/dev/urandom", O_RDONLY);