bootloaders: cleanup

- make printf buffer static and local to printf()
- use '\0' instead of 0 for setting char
- remove unused dummy functions

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30117 a1c6a512-1295-4272-9138-f99709370657
diff --git a/bootloader/common.c b/bootloader/common.c
index 8fb7cde..207d74a 100644
--- a/bootloader/common.c
+++ b/bootloader/common.c
@@ -57,8 +57,6 @@
 int remote_line = 0;
 #endif
 
-char printfbuf[256];
-
 void reset_screen(void)
 {
     lcd_clear_display();
@@ -71,6 +69,7 @@
 
 int printf(const char *format, ...)
 {
+    static char printfbuf[256];
     int len;
     unsigned char *ptr;
     va_list ap;
@@ -185,7 +184,7 @@
     if(rc < 4)
         return EREAD_MODEL_FAILED;
 
-    model[4] = 0;
+    model[4] = '\0';
 
     printf("Model name: %s", model);
     printf("Loading %s", firmware);
@@ -240,17 +239,6 @@
     return len;
 }
 
-/* These functions are present in the firmware library, but we reimplement
-   them here because the originals do a lot more than we want */
-int dbg_ports(void)
-{
-   return 0;
-}
-
-void mpeg_stop(void)
-{
-}
-
 #ifdef ROCKBOX_HAS_LOGF /* Logf display helper for the bootloader */
 
 #define LINES   (LCD_HEIGHT/SYSFONT_HEIGHT)