util/nvmutil: rhex(): fail if errno not zero

The code was only checking whether all of the bytes were read,
but there are other errors that can be caught via errno.

Enforce strict errno handling, when generating random
numbers for command `setmac`.

1 files changed, 2 insertions, 0 deletions

diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c
index 6fb0a1d5..759edea0 100644
--- a/util/nvmutil/nvmutil.c
+++ b/util/nvmutil/nvmutil.c
@@ -258,6 +258,8 @@ rhex(void)
 			warn("%s", "/dev/urandom");
 			return 16;
 		}
+		if ((errno != 0))
+			return 16;
 	}
 
 	return rbuf[rindex++] & 0xf;