util/nvmutil: don't reset errno in check_read_or_die

we want to debug it after the fact; this is now handled,
in the calling functions (unhandled error exceptions).

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/nvmutil/nvmutil.c

@@ -450,9 +450,7 @@ check_read_or_die(const char *rpath, ssize_t rval, size_t rsize,
 
 	/*
 	 * Bad read, with errno EINTR (syscall interrupted).
-	 * Reset the error state and try again.
 	 */
-	errno = 0;
 	return 0;
 }