[2.28] error, error_at_line: Add missing va_end calls

[Florian Weimer]

(cherry picked from commit b7b52b9dec337a08a89bc67638773be652eba332)

2018-08-13  Florian Weimer  <fweimer@redhat.com>

	* misc/error.c (error): Add missing va_end call.
	(error_at_line): Likewise.

diff --git a/misc/error.c b/misc/error.c
index b4e8b6c938..03378e2f2a 100644
--- a/misc/error.c
+++ b/misc/error.c
@@ -319,6 +319,7 @@ error (int status, int errnum, const char *message, ...)
 
   va_start (args, message);
   error_tail (status, errnum, message, args);
+  va_end (args);
 
 #ifdef _LIBC
   _IO_funlockfile (stderr);
@@ -390,6 +391,7 @@ error_at_line (int status, int errnum, const char *file_name,
 
   va_start (args, message);
   error_tail (status, errnum, message, args);
+  va_end (args);
 
 #ifdef _LIBC
   _IO_funlockfile (stderr);