[LyX/master] Simplify code

[Scott Kostyshak]

commit 90772a01e78ff7de2dd27b9284b99b2085542225
Author: Scott Kostyshak <skost...@lyx.org>
Date:   Sat Apr 4 14:56:29 2015 -0400

    Simplify code

diff --git a/src/support/Systemcall.cpp b/src/support/Systemcall.cpp
index 2f277f6..28cbdc8 100644
--- a/src/support/Systemcall.cpp
+++ b/src/support/Systemcall.cpp
@@ -607,13 +607,11 @@ QString SystemcallPrivate::exitStatusMessage() const
 
 int SystemcallPrivate::exitCode()
 {
-       if (!process_)
-               return -1;
-
        // From Qt's documentation, in regards to QProcess::exitCode(),
        // "This value is not valid unless exitStatus() returns NormalExit"
-       if (process_->exitStatus() != QProcess::NormalExit)
+       if (!process_ || process_->exitStatus() != QProcess::NormalExit)
                return -1;
+
        return process_->exitCode();
 }