libssh2_channel_write: show how the macro is defined

docs/libssh2_channel_write.3

@@ -2,12 +2,13 @@
 .\"
 .TH libssh2_channel_write 3 "20 Feb 2010" "libssh2 1.2.4" "libssh2 manual"
 .SH NAME
-libssh2_channel_write - convenience macro for \fIlibssh2_channel_write_ex(3)\fP calls
+libssh2_channel_write - convenience macro for \fIlibssh2_channel_write_ex(3)\fP
 .SH SYNOPSIS
+.nf
 #include <libssh2.h>
 
-libssh2_channel_write(arguments)
-
+#define libssh2_channel_write(channel, buf, buflen) \\
+  libssh2_channel_write_ex((channel), 0, (buf), (buflen))
 .SH DESCRIPTION
 This is a macro defined in a public libssh2 header file that is using the
 underlying function \fIlibssh2_channel_write_ex(3)\fP.