Simplify nullptr comparisons where appropriate

Make the codebase consistent, we already have a lot of implicit pointer comparisons.

Exception: Stay explicit on return's, example:
  return _db != nullptr;

Signed-off-by: Michael Schuster <michael@schuster.ms>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gui/systray.cpp b/src/gui/systray.cpp
index 0c7674d73..66ac956f2 100644
--- a/src/gui/systray.cpp
+++ b/src/gui/systray.cpp
@@ -40,7 +40,7 @@ Systray *Systray::_instance = nullptr;
 
 Systray *Systray::instance()
 {
-    if (_instance == nullptr) {
+    if (!_instance) {
         _instance = new Systray();
     }
     return _instance;