util/nvmutil: tidy up rhex

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

1 files changed, 8 insertions, 3 deletions

diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c
index bcf205c3..73527723 100644
--- a/util/nvmutil/nvmutil.c
+++ b/util/nvmutil/nvmutil.c
@@ -340,9 +340,14 @@ hextonum(char ch)
 static uint8_t
 rhex(void)
 {
-	static uint8_t n = 0, rnum[12];
-	if (!n)
-		err_if(read(rfd, (uint8_t *) &rnum, (n = 11) + 1) == -1);
+	static uint8_t n = 0;
+	static uint8_t rnum[12];
+
+	if (!n) {
+		n = sizeof(rnum) - 1;
+		err_if(read(rfd, (uint8_t *) &rnum, n + 1) == -1);
+	}
+
 	return rnum[n--] & 0xf;
 }