image.c: Modify the code as reviewer suggested and remove FIXME comme…

…nt description

src/image.c

@@ -31,9 +31,7 @@ typedef enum {
 #undef _
 } twin_image_format_t;
 
-/* FIXME: Check the header of the given images to determine the supported image
- * formats instead of parsing the filename without checking its content.
- */
+
 static twin_image_format_t image_type_from_name(const char *path)
 {
     twin_image_format_t type = IMAGE_TYPE_unknown;
@@ -55,20 +53,18 @@ static twin_image_format_t image_type_from_name(const char *path)
 #if LOADER_HAS(PNG)
 #if __BYTE_ORDER == __BIG_ENDIAN
     uint8_t png_header[8] = {0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A};
-    if (memcmp(header, png_header, sizeof(png_header)) == 0) {
-        type = IMAGE_TYPE_png;
-    }
 #else
     uint8_t png_header[8] = {0x0A, 0x1A, 0x0A, 0x0D, 0x47, 0x4E, 0x50, 0x89};
-    if (memcmp(header, png_header, sizeof(png_header)) == 0) {
+#endif
+
+    if (!memcmp(header, png_header, sizeof(png_header))) {
         type = IMAGE_TYPE_png;
     }
 #endif
-#endif
 
 #if LOADER_HAS(JPEG)
     uint8_t jpg_header[3] = {0xFF, 0xD8, 0xFF};
-    if (memcmp(header, jpg_header, sizeof(jpg_header)) == 0) {
+    if (!memcmp(header, jpg_header, sizeof(jpg_header))) {
         type = IMAGE_TYPE_jpeg;
     }
 #endif