[LyX/master] When running latex one needs to have a proper buffer

[Jean-Marc Lasgouttes]

commit f7768c994dc6aa6c79c32a8eee77eaa41662f9a4
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Mon Mar 27 17:43:18 2017 +0200

    When running latex one needs to have a proper buffer
    
    Calms down coverity
---
 src/Converter.cpp |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Converter.cpp b/src/Converter.cpp
index 2f22030..f58a188 100644
--- a/src/Converter.cpp
+++ b/src/Converter.cpp
@@ -463,11 +463,12 @@ bool Converters::convert(Buffer const * buffer,
                        return false;
 
                if (conv.latex()) {
+                       LATTEST(buffer);
                        run_latex = true;
                        string command = conv.command();
                        command = subst(command, token_from, "");
-                       command = subst(command, token_latex_encoding, buffer ?
-                               buffer->params().encoding().latexName() : 
string());
+                       command = subst(command, token_latex_encoding,
+                                       
buffer->params().encoding().latexName());
                        LYXERR(Debug::FILES, "Running " << command);
                        if (!runLaTeX(*buffer, command, runparams, errorList))
                                return false;