gssmask: check return of krb5_init_context

Check the return value so that a more obtuse error does not occur
later on.

Change-Id: I2115cc58e6fc24b63272b2ae811d64a4966de5d4

appl/gssmask/gssmask.c

@@ -1210,6 +1210,7 @@ int
 main(int argc, char **argv)
 {
     int optidx	= 0;
+    krb5_error_code ret;
 
     setprogname (argv[0]);
 
@@ -1235,7 +1236,9 @@ main(int argc, char **argv)
 	    errx (1, "Bad port `%s'", port_str);
     }
 
-    krb5_init_context(&context);
+    ret = krb5_init_context(&context);
+    if (ret)
+	errx(1, "Error initializing kerberos: %d", ret);
 
     {
 	const char *lf = logfile_str;