fxtest.c: In function ‘main’:
fxtest.c:190:3: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
GtkWidget *window;
^~~~~~~~~
When g_option_context_parse fails, context and error variables are not getting free'd
which results in memory leaks. Free'ing the same.
And replacing g_error_free with g_clear_error, which checks if the error being passed
is not NULL and sets the variable to NULL on free'ing.
https://bugzilla.gnome.org/show_bug.cgi?id=753854
