[PATCH v9 6/9] ell/term: Return error on writes if the output descriptor is invalid.

Returns -EBADF for 'putnstr' and 'vdprintf' if the output descriptor
for the terminal is invalid.
---
 ell/term.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/ell/term.c b/ell/term.c
index c867b240090c..7ec92476e14e 100644
--- a/ell/term.c
+++ b/ell/term.c
@@ -391,6 +391,9 @@ LIB_EXPORT int l_term_putnstr(struct l_term *term, const char *str, size_t n)
 	if (!term)
 		return -EINVAL;
 
+	if (term->out_fd < 0)
+		return -EBADF;
+
 	res = write(term->out_fd, str, n);
 	if (res < 0)
 		return -errno;
@@ -432,6 +435,9 @@ LIB_EXPORT int l_term_vprint(struct l_term *term, const char *str, va_list ap)
 	if (!term || !str)
 		return -EINVAL;
 
+	if (term->out_fd < 0)
+		return -EBADF;
+
 	if (vdprintf(term->out_fd, str, ap) < 0)
 		return -errno;
 
-- 
2.45.0