Fix unused-result warning for chdir

Fix unused-result warning for chdir

Fixes this warning:

Source/main.cpp: In function 'void chdirToAppPath(const char*)':
Source/main.cpp:581:14: warning: ignoring return value of 'int chdir(const char*)', declared with attribute warn_unused_result [-Wunused-result]
         chdir(dir);
         ~~~~~^~~~~