This is a trivial cosmetic fix

Without it, the error message might look like: Image size doesnt match:
Success

Corresponding to flashrom svn r95 and coreboot v2 svn r2573.
Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>

flash_rom.c

@@ -345,7 +345,7 @@ int main(int argc, char *argv[])
 			exit(1);
 		}
 		if(image_stat.st_size!=flash->total_size*1024) {
-			perror("Image size doesnt match");
+			fprintf(stderr, "Error: Image size doesnt match\n");
 			exit(1);
 		}