wrong return type for vfs_spiffs_write fixed

Author: loboris

components/spiffs/spiffs_vfs.c

@@ -48,7 +48,7 @@ int spiffs_is_mounted = 0;
 QueueHandle_t spiffs_mutex = NULL;
 
 static int IRAM_ATTR vfs_spiffs_open(const char *path, int flags, int mode);
-static size_t IRAM_ATTR vfs_spiffs_write(int fd, const void *data, size_t size);
+static ssize_t IRAM_ATTR vfs_spiffs_write(int fd, const void *data, size_t size);
 static ssize_t IRAM_ATTR vfs_spiffs_read(int fd, void * dst, size_t size);
 static int IRAM_ATTR vfs_spiffs_fstat(int fd, struct stat * st);
 static int IRAM_ATTR vfs_spiffs_close(int fd);
@@ -263,8 +263,8 @@ static int IRAM_ATTR vfs_spiffs_open(const char *path, int flags, int mode) {
     return fd;
 }
 
-//-------------------------------------------------------------------------------
-static size_t IRAM_ATTR vfs_spiffs_write(int fd, const void *data, size_t size) {
+//--------------------------------------------------------------------------------
+static ssize_t IRAM_ATTR vfs_spiffs_write(int fd, const void *data, size_t size) {
 	vfs_spiffs_file_t *file;
 	int res;