libreboot-utils/lib: loop eintr on [p]read/[p]write

i forgot to do this!

with this, I/O should be bullet proof now.
i already loop this on other I/O commands.

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

util/libreboot-utils/lib/rand.c

@@ -150,7 +150,8 @@ rset(void *buf, size_t n)
 	int fd = -1;
 	open_on_eintr("/dev/urandom", &fd, O_RDONLY, 0400, NULL);
 retry_rand:
-	if ((rc = read(fd, (unsigned char *)buf + off, n - off)) < 0) {
+	if ((rc = read_on_eintr(fd,
+	    (unsigned char *)buf + off, n - off)) < 0) {
 #elif defined(__linux__)
 retry_rand:
 	if ((rc = (ssize_t)syscall(SYS_getrandom,