gpg: Initialize a parameter to silence valgrind.

* g10/keygen.c (read_parameter_file): Initialize nline.
* g10/textfilter.c (copy_clearsig_text): Initialize bufsize.
--

In iobuf_read_line the parameter to pass and return the current buffer
length is controlled by the buffer parameter.  Thus there should be no
problem because the assert call check s buffer first.  For yet unknown
reasons when using the standard GNU libc assert valgrind complains
about an uninitialized variable.  That does not happen with our
log_assert.  Tested with gcc 8.3.0 and valgrind 3.14.0.

g10/keygen.c

@@ -4039,6 +4039,7 @@ read_parameter_file (ctrl_t ctrl, const char *fname )
     para = NULL;
     maxlen = 1024;
     line = NULL;
+    nline = 0;
     while ( iobuf_read_line (fp, &line, &nline, &maxlen) ) {
 	char *keyword, *value;