Fix most of the warnings in the macos builds

src/chipset/ali1543.c

@@ -489,12 +489,10 @@ static void
 ali5229_ide_irq_handler(ali1543_t *dev)
 {
     int ctl = 0;
-    int ch = 0;
     int bit = 0;
 
     if (dev->ide_conf[0x52] & 0x10) {
         ctl ^= 1;
-        ch ^= 1;
         bit ^= 5;
     }
 

src/qt/qt_renderercommon.cpp

@@ -88,7 +88,7 @@ RendererCommon::onResize(int width, int height)
 
                 if (video_fullscreen_scale == FULLSCR_SCALE_INT43) {
                     gh = gw / r43;
-                    gw = gw;
+//                  gw = gw;
 
                     gsr = r43;
                 }

src/unix/unix.c

@@ -830,7 +830,7 @@ plat_init_rom_paths(void)
         rom_add_path("/usr/share/86Box/roms/");
     }
 #else
-    char  default_rom_path[1024] = { '\0 ' };
+    char  default_rom_path[1024] = { '\0' };
     getDefaultROMPath(default_rom_path);
     rom_add_path(default_rom_path);
 #endif