env: Fix documentation for env_get_f()

This function actually returns:
- the number of bytes written into @buf excluding the terminating
  NULL-byte, if there was enough space in @buf
- the number of bytes written into @buf including the terminating
  NULL-byte, if there wasn't enough space in @buf
- -1 if the variable is not found

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/env.h b/include/env.h
index d5e2bcb..b1a4003 100644
--- a/include/env.h
+++ b/include/env.h
@@ -131,7 +131,10 @@ char *from_env(const char *envvar);
  * support reading the value (slowly) and some will not.
  *
  * @varname:	Variable to look up
- * @return value of variable, or NULL if not found
+ * @return number of bytes written into @buf, excluding the terminating
+ *	NULL-byte if there was enough space in @buf, and including the
+ *	terminating NULL-byte if there wasn't enough space, or -1 if the
+ *	variable is not found
  */
 int env_get_f(const char *name, char *buf, unsigned int len);