Fix warning of pointer type mismatch

diff --git a/lib/cgraph/io.c b/lib/cgraph/io.c
index 7ccffe2877144b84b6c071da9508db9314d0e7b2..51e6bd91dc55aa6b6c00e92082433673bcd418f0 100644 (file)
--- a/lib/cgraph/io.c
+++ b/lib/cgraph/io.c
@@ -73,7 +73,7 @@ static int iofread(void *chan, char *buf, int bufsize)
 }
 
 /* default IO methods */
-static int ioputstr(void *chan, char *str)
+static int ioputstr(void *chan, const char *str)
 {
     return fputs(str, (FILE *) chan);
 }